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A Day Has Only 241 Hours Miroslav ediv eumiro 1 / 73 A Day Has - - PowerPoint PPT Presentation

Jan 31, 2024 113 likes •847 views

A Day Has Only 241 Hours Miroslav ediv eumiro 1 / 73 A Day Has Only 241 Hours eumiro soluteTech 2 / 73 A Day Has Only 241 Hours check the time eumiro soluteTech 3 / 73 A Day Has Only 241 Hours check the time

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A Day Has Only 24±1 Hours

Miroslav Šedivý

 eumiro

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A Day Has Only 24±1 Hours

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A Day Has Only 24±1 Hours

check the time  eumiro  soluteTech 3 / 73

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A Day Has Only 24±1 Hours

check the time don't check the time too often  eumiro  soluteTech 4 / 73

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A Day Has Only 24±1 Hours

check the time don't check the time too often check what your government does  eumiro  soluteTech 5 / 73

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SLIDE 6

Miroslav Šedivý

[ˈmɪrɔslaʋ ˈʃɛɟɪviː]  eumiro  soluteTech 6 / 73

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Miroslav Šedivý

[ˈmɪrɔslaʋ ˈʃɛɟɪviː] born in Bratislava, Czechoslovakia (TZ=Europe/Bratislava)  eumiro  soluteTech 7 / 73

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SLIDE 8

Miroslav Šedivý

[ˈmɪrɔslaʋ ˈʃɛɟɪviː] born in Bratislava, Czechoslovakia (TZ=Europe/Bratislava) M.Sc. at INSA Lyon, France (TZ=Europe/Paris)  eumiro  soluteTech 8 / 73

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Miroslav Šedivý

[ˈmɪrɔslaʋ ˈʃɛɟɪviː] born in Bratislava, Czechoslovakia (TZ=Europe/Bratislava) M.Sc. at INSA Lyon, France (TZ=Europe/Paris) Senior Software Developer at solute GmbH, Karlsruhe, Germany (TZ=Europe/Berlin)  eumiro  soluteTech 9 / 73

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Miroslav Šedivý

[ˈmɪrɔslaʋ ˈʃɛɟɪviː] born in Bratislava, Czechoslovakia (TZ=Europe/Bratislava) M.Sc. at INSA Lyon, France (TZ=Europe/Paris) Senior Software Developer at solute GmbH, Karlsruhe, Germany (TZ=Europe/Berlin)

The whole life in the CE(S)T!

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SLIDE 11

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Thursday, 11th July 2019 10:33 CEST (Basel, Switzerland)

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>>> import datetime >>> datetime.datetime.now() datetime.datetime(2019, 7, 11, 10, 33, 0, 0)

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>>> import datetime >>> datetime.datetime.now() datetime.datetime(2019, 7, 11, 10, 33, 0, 0) datetime.datetime(2019, 7, 11, 8, 33, 0, 0) # server set to UTC

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SLIDE 15

>>> import datetime >>> datetime.datetime.now() datetime.datetime(2019, 7, 11, 10, 33, 0, 0) datetime.datetime(2019, 7, 11, 8, 33, 0, 0) # server set to UTC >>> datetime.datetime.utcnow() datetime.datetime(2019, 7, 11, 8, 33, 0, 0)

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>>> import datetime >>> datetime.datetime.now() datetime.datetime(2019, 7, 11, 10, 33, 0, 0) datetime.datetime(2019, 7, 11, 8, 33, 0, 0) # server set to UTC >>> datetime.datetime.utcnow() datetime.datetime(2019, 7, 11, 8, 33, 0, 0) >>> datetime.datetime.now(datetime.timezone.utc) datetime.datetime(2019, 7, 11, 8, 33, 0, 0, tzinfo=datetime.timezone.utc)

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>>> import datetime >>> datetime.datetime.now() datetime.datetime(2019, 7, 11, 10, 33, 0, 0) datetime.datetime(2019, 7, 11, 8, 33, 0, 0) # server set to UTC >>> datetime.datetime.utcnow() datetime.datetime(2019, 7, 11, 8, 33, 0, 0) >>> datetime.datetime.now(datetime.timezone.utc) datetime.datetime(2019, 7, 11, 8, 33, 0, 0, tzinfo=datetime.timezone.utc) >>> datetime.datetime.now(datetime.timezone(datetime.timedelta(hours=2))) datetime.datetime(2019, 7, 11, 10, 33, 0, 0, tzinfo=datetime.timezone(datetime.timedelta(0, 7200)))

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>>> import datetime >>> datetime.datetime.now() datetime.datetime(2019, 7, 11, 10, 33, 0, 0) datetime.datetime(2019, 7, 11, 8, 33, 0, 0) # server set to UTC >>> datetime.datetime.utcnow() datetime.datetime(2019, 7, 11, 8, 33, 0, 0) >>> datetime.datetime.now(datetime.timezone.utc) datetime.datetime(2019, 7, 11, 8, 33, 0, 0, tzinfo=datetime.timezone.utc) >>> datetime.datetime.now(datetime.timezone(datetime.timedelta(hours=2))) datetime.datetime(2019, 7, 11, 10, 33, 0, 0, tzinfo=datetime.timezone(datetime.timedelta(0, 7200))) >>> import pytz >>> datetime.datetime.now(pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, 0, 0, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>)

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>>> datetime.datetime.now(pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, 0, 0, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>)

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>>> datetime.datetime.now(pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, 0, 0, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>) >>> datetime.datetime(2019, 7, 11, 10, 33, 0, 0, pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' LMT+0:34:00 STD>)

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>>> datetime.datetime.now(pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, 0, 0, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>) >>> datetime.datetime(2019, 7, 11, 10, 33, 0, 0, pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' LMT+0:34:00 STD>) >>> pytz.timezone('Europe/Zurich').localize(datetime.datetime(2019, 7, 11, 10, 33, 0, 0)) datetime.datetime(2019, 7, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>)

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>>> datetime.datetime.now(pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, 0, 0, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>) >>> datetime.datetime(2019, 7, 11, 10, 33, 0, 0, pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' LMT+0:34:00 STD>) >>> pytz.timezone('Europe/Zurich').localize(datetime.datetime(2019, 7, 11, 10, 33, 0, 0)) datetime.datetime(2019, 7, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>) >>> now + datetime.timedelta(days=184) datetime.datetime(2020, 1, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>)

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>>> datetime.datetime.now(pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, 0, 0, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>) >>> datetime.datetime(2019, 7, 11, 10, 33, 0, 0, pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' LMT+0:34:00 STD>) >>> pytz.timezone('Europe/Zurich').localize(datetime.datetime(2019, 7, 11, 10, 33, 0, 0)) datetime.datetime(2019, 7, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>) >>> now + datetime.timedelta(days=184) datetime.datetime(2020, 1, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>) >>> pytz.timezone('Europe/Zurich').normalize(now + datetime.timedelta(days=184)) datetime.datetime(2020, 1, 11, 9, 33, tzinfo=<DstTzInfo 'Europe/Zurich' CET+1:00:00 STD>)

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>>> datetime.datetime.now(pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, 0, 0, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>) >>> datetime.datetime(2019, 7, 11, 10, 33, 0, 0, pytz.timezone('Europe/Zurich')) datetime.datetime(2019, 7, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' LMT+0:34:00 STD>) >>> pytz.timezone('Europe/Zurich').localize(datetime.datetime(2019, 7, 11, 10, 33, 0, 0)) datetime.datetime(2019, 7, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>) >>> now + datetime.timedelta(days=184) datetime.datetime(2020, 1, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' CEST+2:00:00 DST>) >>> pytz.timezone('Europe/Zurich').normalize(now + datetime.timedelta(days=184)) datetime.datetime(2020, 1, 11, 9, 33, tzinfo=<DstTzInfo 'Europe/Zurich' CET+1:00:00 STD>) >>> pytz.timezone('Europe/Zurich').localize(now.replace(tzinfo=None) + datetime.timedelta(days=184)) datetime.datetime(2020, 1, 11, 10, 33, tzinfo=<DstTzInfo 'Europe/Zurich' CET+1:00:00 STD>)

 eumiro  soluteTech 24 / 73

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>>> date = datetime.datetime.utcnow().strftime('%Y-%m-%d') >>> weekday = datetime.datetime.utcnow().strftime('%A') '2019-07-11' 'Thursday'

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>>> date = datetime.datetime.utcnow().strftime('%Y-%m-%d') >>> weekday = datetime.datetime.utcnow().strftime('%A') '2019-07-11' 'Thursday' >>> now = datetime.datetime.utcnow() >>> date = now.strftime('%Y-%m-%d') >>> weekday = now.strftime('%A')

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>>> date = datetime.datetime.utcnow().strftime('%Y-%m-%d') >>> weekday = datetime.datetime.utcnow().strftime('%A') '2019-07-11' 'Thursday' >>> now = datetime.datetime.utcnow() >>> date = now.strftime('%Y-%m-%d') >>> weekday = now.strftime('%A')

Check the time only once!

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>>> start = datetime.datetime.utcnow() # datetime.datetime(2019, 7, 11, 8, 33, 0, 0) >>> expensive_operation() >>> end = datetime.datetime.utcnow() # datetime.datetime(2019, 7, 11, 8, 33, 1, 0) >>> elapsed = (end - start).total_seconds() # datetime.timedelta(seconds=1) -> 1.0

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>>> start = datetime.datetime.utcnow() # datetime.datetime(2019, 7, 11, 8, 33, 0, 0) >>> expensive_operation() >>> end = datetime.datetime.utcnow() # datetime.datetime(2019, 7, 11, 8, 33, 1, 0) >>> elapsed = (end - start).total_seconds() # datetime.timedelta(seconds=1) -> 1.0 >>> start = time.time() # 1562833980.0 >>> expensive_operation() >>> end = time.time() # 1562833981.0 >>> elapsed = end - start

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>>> start = datetime.datetime.utcnow() # datetime.datetime(2019, 7, 11, 8, 33, 0, 0) >>> expensive_operation() >>> end = datetime.datetime.utcnow() # datetime.datetime(2019, 7, 11, 8, 33, 1, 0) >>> elapsed = (end - start).total_seconds() # datetime.timedelta(seconds=1) -> 1.0 >>> start = time.time() # 1562833980.0 >>> expensive_operation() >>> end = time.time() # 1562833981.0 >>> elapsed = end - start >>> start = time.monotonic() # 5.0 >>> expensive_operation() >>> end = time.monotonic() # 6.0 >>> elapsed = end - start

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>>> start = datetime.datetime.utcnow() # datetime.datetime(2019, 7, 11, 8, 33, 0, 0) >>> expensive_operation() >>> end = datetime.datetime.utcnow() # datetime.datetime(2019, 7, 11, 8, 33, 1, 0) >>> elapsed = (end - start).total_seconds() # datetime.timedelta(seconds=1) -> 1.0 >>> start = time.time() # 1562833980.0 >>> expensive_operation() >>> end = time.time() # 1562833981.0 >>> elapsed = end - start >>> start = time.monotonic() # 5.0 >>> expensive_operation() >>> end = time.monotonic() # 6.0 >>> elapsed = end - start >>> time.monotonic_ns() # 6000000000 (Python 3.7+)

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>>> import pytz >>> len(pytz.common_timezones) 440

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>>> import pytz >>> len(pytz.common_timezones) 440

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https://www.iana.org/time-zones

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https://www.iana.org/time-zones tzdata2019b.tar.gz (2019-07-01, 376kB)

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https://www.iana.org/time-zones tzdata2019b.tar.gz (2019-07-01, 376kB)

60867 Jun 17 09:02 africa 252 May 25 2017 LICENSE 12975 Jun 17 09:02 antarctica 43192 Jul 1 09:06 Makefile 161159 Jun 29 19:49 asia 173668 Jul 1 09:11 NEWS 90597 Jun 17 09:02 australasia 154701 Jun 27 02:31 northamerica 4606 Mar 8 20:28 backward 1249 Jun 17 09:02 pacificnew 21969 Jun 17 09:02 backzone 2351 Feb 1 00:37 README 5567 Oct 2 2017 calendars 88328 Jun 17 09:02 southamerica 1008 Jun 2 2017 checklinks.awk 1594 Jun 17 09:02 systemv 4473 Jun 22 22:55 checktab.awk 57262 Jun 27 02:29 theory.html 3042 Oct 5 2018 CONTRIBUTING 6 Jul 1 09:11 version 2768 Mar 8 20:28 etcetera 753 Jul 16 2018 yearistype.sh 172345 Jun 27 02:31 europe 3694 Nov 1 2018 ziguard.awk 404 Jun 17 09:02 factory 8446 May 17 00:18 zishrink.awk 4463 Feb 20 00:30 iso3166.tab 17938 Jun 22 21:39 zone1970.tab 2568 Jan 31 19:33 leapseconds 1453 Jun 17 09:02 zoneinfo2tdf.pl 3645 Nov 10 2018 leapseconds.awk 19424 Jun 22 21:39 zone.tab 10667 Jan 31 19:33 leap-seconds.list

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SLIDE 40

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Europe/Zurich

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Europe/Zurich

Zone Europe/Zurich 0:34:08 - LMT 1853 Jul 16 0:29:46 - BMT 1894 Jun 1:00 Swiss CE%sT 1981 1:00 EU CE%sT

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Europe/Zurich

Zone Europe/Zurich 0:34:08 - LMT 1853 Jul 16 0:29:46 - BMT 1894 Jun 1:00 Swiss CE%sT 1981 1:00 EU CE%sT Rule Swiss 1941 1942 - May Mon>=1 1:00 1:00 S Rule Swiss 1941 1942 - Oct Mon>=1 2:00 0 -

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Europe/Zurich

Zone Europe/Zurich 0:34:08 - LMT 1853 Jul 16 0:29:46 - BMT 1894 Jun 1:00 Swiss CE%sT 1981 1:00 EU CE%sT Rule Swiss 1941 1942 - May Mon>=1 1:00 1:00 S Rule Swiss 1941 1942 - Oct Mon>=1 2:00 0 - Rule EU 1977 1980 - Apr Sun>=1 1:00u 1:00 S Rule EU 1977 only - Sep lastSun 1:00u 0 - Rule EU 1978 only - Oct 1 1:00u 0 - Rule EU 1979 1995 - Sep lastSun 1:00u 0 - Rule EU 1981 max - Mar lastSun 1:00u 1:00 S Rule EU 1996 max - Oct lastSun 1:00u 0 -

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Europe/Zurich

Zone Europe/Zurich 0:34:08 - LMT 1853 Jul 16 0:29:46 - BMT 1894 Jun 1:00 Swiss CE%sT 1981 1:00 EU CE%sT Rule Swiss 1941 1942 - May Mon>=1 1:00 1:00 S Rule Swiss 1941 1942 - Oct Mon>=1 2:00 0 - Rule EU 1977 1980 - Apr Sun>=1 1:00u 1:00 S Rule EU 1977 only - Sep lastSun 1:00u 0 - Rule EU 1978 only - Oct 1 1:00u 0 - Rule EU 1979 1995 - Sep lastSun 1:00u 0 - Rule EU 1981 max - Mar lastSun 1:00u 1:00 S Rule EU 1996 max - Oct lastSun 1:00u 0 - Link Europe/Zurich Europe/Vaduz

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Europe/Zurich

Zone Europe/Zurich 0:34:08 - LMT 1853 Jul 16 0:29:46 - BMT 1894 Jun 1:00 Swiss CE%sT 1981 1:00 EU CE%sT Rule Swiss 1941 1942 - May Mon>=1 1:00 1:00 S Rule Swiss 1941 1942 - Oct Mon>=1 2:00 0 - Rule EU 1977 1980 - Apr Sun>=1 1:00u 1:00 S Rule EU 1977 only - Sep lastSun 1:00u 0 - Rule EU 1978 only - Oct 1 1:00u 0 - Rule EU 1979 1995 - Sep lastSun 1:00u 0 - Rule EU 1981 max - Mar lastSun 1:00u 1:00 S Rule EU 1996 max - Oct lastSun 1:00u 0 - Link Europe/Zurich Europe/Vaduz Link Europe/Zurich Europe/Busingen

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Zone Europe/Berlin 0:53:28 - LMT 1893 Apr 1:00 C-Eur CE%sT 1945 May 24 2:00 1:00 SovietZone CE%sT 1946 1:00 Germany CE%sT 1980 1:00 EU CE%sT

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Zone Europe/Berlin 0:53:28 - LMT 1893 Apr 1:00 C-Eur CE%sT 1945 May 24 2:00 1:00 SovietZone CE%sT 1946 1:00 Germany CE%sT 1980 1:00 EU CE%sT Zone Europe/Paris 0:09:21 - LMT 1891 Mar 15 0:01 0:09:21 - PMT 1911 Mar 11 0:01 # Paris MT 0:00 France WE%sT 1940 Jun 14 23:00 1:00 C-Eur CE%sT 1944 Aug 25 0:00 France WE%sT 1945 Sep 16 3:00 1:00 France CE%sT 1977 1:00 EU CE%sT

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Zone Europe/Berlin 0:53:28 - LMT 1893 Apr 1:00 C-Eur CE%sT 1945 May 24 2:00 1:00 SovietZone CE%sT 1946 1:00 Germany CE%sT 1980 1:00 EU CE%sT Zone Europe/Paris 0:09:21 - LMT 1891 Mar 15 0:01 0:09:21 - PMT 1911 Mar 11 0:01 # Paris MT 0:00 France WE%sT 1940 Jun 14 23:00 1:00 C-Eur CE%sT 1944 Aug 25 0:00 France WE%sT 1945 Sep 16 3:00 1:00 France CE%sT 1977 1:00 EU CE%sT # Amsterdam Mean Time was +00:19:32.13, but the .13 is omitted # below because the current format requires STDOFF to be an integer. Zone Europe/Amsterdam 0:19:32 - LMT 1835 0:19:32 Neth %s 1937 Jul 1 0:20 Neth +0020/+0120 1940 May 16 0:00 1:00 C-Eur CE%sT 1945 Apr 2 2:00 1:00 Neth CE%sT 1977 1:00 EU CE%sT

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Europe/Istanbul

Link Europe/Istanbul Asia/Istanbul # Istanbul is in both continents.

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Europe/Istanbul

Link Europe/Istanbul Asia/Istanbul # Istanbul is in both continents. Zone Europe/Istanbul 1:55:52 - LMT 1880 1:56:56 - IMT 1910 Oct # Istanbul Mean Time? 2:00 Turkey EE%sT 1978 Oct 15 3:00 Turkey +03/+04 1985 Apr 20 2:00 Turkey EE%sT 2007 2:00 EU EE%sT 2011 Mar 27 1:00u 2:00 - EET 2011 Mar 28 1:00u 2:00 EU EE%sT 2014 Mar 30 1:00u 2:00 - EET 2014 Mar 31 1:00u 2:00 EU EE%sT 2015 Oct 25 1:00u 2:00 1:00 EEST 2015 Nov 8 1:00u 2:00 EU EE%sT 2016 Sep 7 3:00 - +03

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Europe/Istanbul

Link Europe/Istanbul Asia/Istanbul # Istanbul is in both continents. Zone Europe/Istanbul 1:55:52 - LMT 1880 1:56:56 - IMT 1910 Oct # Istanbul Mean Time? 2:00 Turkey EE%sT 1978 Oct 15 3:00 Turkey +03/+04 1985 Apr 20 2:00 Turkey EE%sT 2007 2:00 EU EE%sT 2011 Mar 27 1:00u 2:00 - EET 2011 Mar 28 1:00u 2:00 EU EE%sT 2014 Mar 30 1:00u 2:00 - EET 2014 Mar 31 1:00u 2:00 EU EE%sT 2015 Oct 25 1:00u 2:00 1:00 EEST 2015 Nov 8 1:00u 2:00 EU EE%sT 2016 Sep 7 3:00 - +03

(2011-03-10): […] Turkey will change into summer time zone (GMT+3) on March 28, 2011 at 3:00 a.m. instead of March 27. This change is due to a nationwide exam on 27th. [URL] Turkish: [URL]  eumiro  soluteTech 54 / 73

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2:00 EU EE%sT 2014 Mar 30 1:00u 2:00 - EET 2014 Mar 31 1:00u

[…] (2014-02-14): The DST for Turkey has been changed for this year because of the Turkish Local election.... [URL] ... so Turkey will move clocks forward one hour on March 31 at 3:00 a.m. […] (2014-04-15): Having landed on a flight from the states to Istanbul (via AMS) on March 31, I can tell you that NOBODY (even the airlines) respected this timezone DST change delay. Maybe the word just didn't get out in time. […] (2014-06-15): The press reported massive confusion, as election officials obeyed the rule change but cell phones (and airline baggage systems) did not. See: [URL from 2014-03-30] I guess the best we can do is document the official time.  eumiro  soluteTech 55 / 73

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2:00 EU EE%sT 2015 Oct 25 1:00u 2:00 1:00 EEST 2015 Nov 8 1:00u

[…] (2015-09-29): It's officially announced now by the Ministry of Energy. Turkey delays winter time to 8th of November 04:00 [URL] BBC News (2015-10-25): Confused Turks are asking "what's the time?" after automatic clocks defied a government decision ... "For the next two weeks #Turkey is on EEST... Erdogan Engineered Standard Time," said Twitter user @aysekarahasan. [URL]  eumiro  soluteTech 56 / 73

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2:00 EU EE%sT 2016 Sep 7 3:00 - +03

[…] (2016-09-08): Turkey will stay in Daylight Saving Time even in winter.... [URL] […] (2016-09-07): The change is permanent, so this is the new standard time in Turkey. It takes effect today, which is not much notice. […] (2017-10-28): Turkey will go back to Daylight Saving Time starting 2018-10. [URL] […] (2017-11-08): ... today it was announced that the DST will become "continuous": [URL] […] (2017-11-08): Although Google Translate misfires on that source, it looks like Turkey reversed last month's decision, and so will stay at +03.  eumiro  soluteTech 57 / 73

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America/Caracas

Zone America/Caracas -4:27:44 - LMT 1890

  • 4:27:40 - CMT 1912 Feb 12 # Caracas Mean Time?
  • 4:30 - -0430 1965 Jan 1 0:00
  • 4:00 - -04 2007 Dec 9 3:00
  • 4:30 - -0430 2016 May 1 2:30
  • 4:00 - -04

[…] (2016-04-15): Clocks advance 30 minutes on 2016-05-01 at 02:30.... […] [URL from Reuters] […] (2016-04-20): ... published in the official Gazette [2016-04-18], here: [URL from .ve]  eumiro  soluteTech 58 / 73

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America/Port-au-Prince

Rule Haiti 2005 2006 - Apr Sun>=1 0:00 1:00 D Rule Haiti 2005 2006 - Oct lastSun 0:00 0 S Rule Haiti 2012 2015 - Mar Sun>=8 2:00 1:00 D Rule Haiti 2012 2015 - Nov Sun>=1 2:00 0 S Rule Haiti 2017 max - Mar Sun>=8 2:00 1:00 D Rule Haiti 2017 max - Nov Sun>=1 2:00 0 S

[…] (2005-04-15) […] wrote me that Haiti is now on DST. I searched for confirmation, and I found a press release on the Web page of the Haitian Consulate in Chicago (2005-03-31), […] […] (2006-04-04) I have been informed by users that Haiti observes DST this year like last year […] […] (2012-03-11) According to several news sources, Haiti will observe DST this year, apparently using the same start and end date as USA/Canada. […] […] (2013-03-10) It appears that Haiti is observing DST this year as well, same rules as US/Canada. They did it last year as well, and it looks like they are going to observe DST every year now... […] […] (2016-03-12) […] informed us that Haiti are not going on DST this year. […] […] (2017-03-12) We have received 4 mails from different people telling that Haiti has started DST again today, and this source seems to confirm that, I have not been able to find a more authoritative source: [URL]  eumiro  soluteTech 59 / 73

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SLIDE 60

Asia/Seoul, Asia/Pyongyang

Zone Asia/Seoul 8:27:52 - LMT 1908 Apr 1 | Zone Asia/Pyongyang 8:23:00 - LMT 1908 Apr 1 8:30 - KST 1912 Jan 1 | 8:30 - KST 1912 Jan 1 9:00 - JST 1945 Sep 8 | 9:00 - JST 1945 Aug 24 9:00 - KST 1954 Mar 21 | 9:00 - KST 2015 Aug 15 00:00 8:30 ROK K%sT 1961 Aug 10 | 8:30 - KST 2018 May 4 23:30 9:00 ROK K%sT | 9:00 - KST

 eumiro  soluteTech 60 / 73

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SLIDE 61

Asia/Seoul, Asia/Pyongyang

Zone Asia/Seoul 8:27:52 - LMT 1908 Apr 1 | Zone Asia/Pyongyang 8:23:00 - LMT 1908 Apr 1 8:30 - KST 1912 Jan 1 | 8:30 - KST 1912 Jan 1 9:00 - JST 1945 Sep 8 | 9:00 - JST 1945 Aug 24 9:00 - KST 1954 Mar 21 | 9:00 - KST 2015 Aug 15 00:00 8:30 ROK K%sT 1961 Aug 10 | 8:30 - KST 2018 May 4 23:30 9:00 ROK K%sT | 9:00 - KST

[…] (2015-08-07) According to many news sources, North Korea is going to change to the 8:30 time zone on August 15 […] (2015-08-15) Bells rang out midnight (00:00) Friday as part of the celebrations. […]  eumiro  soluteTech 61 / 73

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SLIDE 62

Asia/Seoul, Asia/Pyongyang

Zone Asia/Seoul 8:27:52 - LMT 1908 Apr 1 | Zone Asia/Pyongyang 8:23:00 - LMT 1908 Apr 1 8:30 - KST 1912 Jan 1 | 8:30 - KST 1912 Jan 1 9:00 - JST 1945 Sep 8 | 9:00 - JST 1945 Aug 24 9:00 - KST 1954 Mar 21 | 9:00 - KST 2015 Aug 15 00:00 8:30 ROK K%sT 1961 Aug 10 | 8:30 - KST 2018 May 4 23:30 9:00 ROK K%sT | 9:00 - KST

[…] (2015-08-07) According to many news sources, North Korea is going to change to the 8:30 time zone on August 15 […] (2015-08-15) Bells rang out midnight (00:00) Friday as part of the celebrations. […] […] (2018-04-29) North Korea will revert its time zone from UTC+8:30 (PYT; Pyongyang Time) back to UTC+9 (KST; Korea Standard Time). […] (2018-04-30) […] It appears to be the front page story at the top in the right-most column.  eumiro  soluteTech 62 / 73

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SLIDE 63

 eumiro  soluteTech 63 / 73

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SLIDE 64

https://www.iana.org/time-zones tzdata2019b.tar.gz (2019-07-01, 376kB)

60867 Jun 17 09:02 africa 252 May 25 2017 LICENSE 12975 Jun 17 09:02 antarctica 43192 Jul 1 09:06 Makefile 161159 Jun 29 19:49 asia 173668 Jul 1 09:11 NEWS 90597 Jun 17 09:02 australasia 154701 Jun 27 02:31 northamerica 4606 Mar 8 20:28 backward 1249 Jun 17 09:02 pacificnew 21969 Jun 17 09:02 backzone 2351 Feb 1 00:37 README 5567 Oct 2 2017 calendars 88328 Jun 17 09:02 southamerica 1008 Jun 2 2017 checklinks.awk 1594 Jun 17 09:02 systemv 4473 Jun 22 22:55 checktab.awk 57262 Jun 27 02:29 theory.html 3042 Oct 5 2018 CONTRIBUTING 6 Jul 1 09:11 version 2768 Mar 8 20:28 etcetera 753 Jul 16 2018 yearistype.sh 172345 Jun 27 02:31 europe 3694 Nov 1 2018 ziguard.awk 404 Jun 17 09:02 factory 8446 May 17 00:18 zishrink.awk 4463 Feb 20 00:30 iso3166.tab 17938 Jun 22 21:39 zone1970.tab 2568 Jan 31 19:33 leapseconds 1453 Jun 17 09:02 zoneinfo2tdf.pl 3645 Nov 10 2018 leapseconds.awk 19424 Jun 22 21:39 zone.tab 10667 Jan 31 19:33 leap-seconds.list

 eumiro  soluteTech 64 / 73

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SLIDE 65

Europe after 2021?  eumiro  soluteTech 65 / 73

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SLIDE 66

Europe/Zurich

Zone Europe/Zurich 0:34:08 - LMT 1853 Jul 16 0:29:46 - BMT 1894 Jun 1:00 Swiss CE%sT 1981 1:00 EU CE%sT Rule EU 1977 1980 - Apr Sun>=1 1:00u 1:00 S Rule EU 1977 only - Sep lastSun 1:00u 0 - Rule EU 1978 only - Oct 1 1:00u 0 - Rule EU 1979 1995 - Sep lastSun 1:00u 0 - Rule EU 1981 max - Mar lastSun 1:00u 1:00 S Rule EU 1996 max - Oct lastSun 1:00u 0 -

 eumiro  soluteTech 66 / 73

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SLIDE 67

Europe/Zurich

Zone Europe/Zurich 0:34:08 - LMT 1853 Jul 16 0:29:46 - BMT 1894 Jun 1:00 Swiss CE%sT 1981 1:00 EU CE%sT Rule EU 1977 1980 - Apr Sun>=1 1:00u 1:00 S Rule EU 1977 only - Sep lastSun 1:00u 0 - Rule EU 1978 only - Oct 1 1:00u 0 - Rule EU 1979 1995 - Sep lastSun 1:00u 0 - Rule EU 1981 2021 - Mar lastSun 1:00u 1:00 S Rule EU 1996 2021 - Oct lastSun 1:00u 0 -

 eumiro  soluteTech 67 / 73

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SLIDE 68

Best practices

don't invent your own time zones  eumiro  soluteTech 68 / 73

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SLIDE 69

Best practices

don't invent your own time zones don't hard code any rules  eumiro  soluteTech 69 / 73

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SLIDE 70

Best practices

don't invent your own time zones don't hard code any rules keep your time zone libs up-to-date  eumiro  soluteTech 70 / 73

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SLIDE 71

Best practices

don't invent your own time zones don't hard code any rules keep your time zone libs up-to-date follow your government's intentions to modify your time zone and inform tz@iana.org  eumiro  soluteTech 71 / 73

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SLIDE 72

Best practices

don't invent your own time zones don't hard code any rules keep your time zone libs up-to-date follow your government's intentions to modify your time zone and inform tz@iana.org AVOID TIME ZONES IF YOU CAN!  eumiro  soluteTech 72 / 73

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SLIDE 73

Best practices

don't invent your own time zones don't hard code any rules keep your time zone libs up-to-date follow your government's intentions to modify your time zone and inform tz@iana.org AVOID TIME ZONES IF YOU CAN!

Miroslav Šedivý

 eumiro  soluteTech 73 / 73