Troublesome Dates

Dates that cause trouble with computers or are significant to computers.

Issues related to dates in the far future will be collected somewhere else.

Also see Troublesome Times.

January 1, 1601

base for FILETIME structure

September 3, 1752 to September 13, 1752

September 3, 1752 to September 13, 1752 were skipped when switching from Julian calendar to Gregorian calendar.

• https://www.mentalfloss.com/article/51370/why-our-calendars-skipped-11-days-1752

November 17, 1858

Why is Wednesday, November 17, 1858 the base time for OpenVMS?

• https://www.slac.stanford.edu/~rkj/crazytime.txt

• https://news.ycombinator.com/item?id=21967830

January 0 1900 (December 30, 1899)

Excel stores dates and times as a number representing the number of days since 1900-Jan-0.

• http://www.cpearson.com/excel/datetime.htm

• https://www.explainxkcd.com/wiki/index.php/2676:_Historical_Dates

February 29, 1900

This is because Excel behaves as if the date 1900-Feb-29 existed. It did not.

• http://www.cpearson.com/excel/datetime.htm

December 13, 1901

The next second this counter can represent is 20:45:52 UTC on December 13, 1901.

• https://www.theregister.com/2024/02/09/it_incident_report_the_clock/

December 31 1903 / January 0, 1904

…but Excel can also treat the date portion of a serial date as the number of days since 1904-Jan-0.

• http://www.cpearson.com/excel/datetime.htm

January 1, 1904

old Macintosh epoch

• https://lowendmac.com/lab/04/0115.html

1912

start of Taiwan calendar

• http://phys.org/news/2010-06-y2k-style-bug-looms-taiwan.html

• https://en.wikipedia.org/wiki/Republic_of_China_calendar

December 31, 1927

• Why is subtracting these two times (in 1927) giving a strange result?

January 1, 1970 (December 31, 1969)

• Unix epoch

• http://arstechnica.com/apple/2016/02/64-bit-iphones-and-ipads-get-stuck-in-a-loop-when-set-to-january-1-1970/

• https://www.explainxkcd.com/wiki/index.php/2676:_Historical_Dates

January 1, 1971

• original Unix epoch

January 4, 1975

On 4 January 1975, the 12-bit field that had been used for dates in the DECsystem-10 operating systems overflowed.

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_1975

April 4, 1975

…but the developer who fixed the bug decided to be a bit clever: He chose April 4, 1975, the date of Microsoft’s founding.

• https://devblogs.microsoft.com/oldnewthing/20160209-00/?p=93002

1978

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_1978

January 6, 1980

GPS epoch

September 18, 1989

2^16 days since January 1 1900

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_1989

September 18, 1993

• https://www.benshoof.org/blog/sierras-macintosh-timebomb
• https://en.m.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_1993

firstDIVUWithA8C0Overflows = 2831155200

January 1 1904 (old Macintosh epoch) + firstDIVUWithA8C0Overflows = September 18 1993

October 29, 1995

• http://rachelbythebay.com/w/2020/10/07/wintime/

November 2, 1997

Around April First of this year reports started circulating in the Apollo Usenet newsgroup of a “date bug” in Domain/OS that would render all Apollo workstations useless after November 2, 1997.

In[178]:= DateList[{1980, 1, 1}];
DatePlus[%, Quantity[ (4*2^47)/10^6 , "Second"]]

Out[179]= {1997, 11, 2, 14, 59, 13.4213}

• https://web.archive.org/web/19970625170249/http://www.interworks.org/Tech/apollonov2/

• https://jim.rees.org/apollo-archive/date-bug

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_1997

1999

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_1999

2000

Y2K

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2000

• https://www.reddit.com/r/mildlyinteresting/comments/laij6n/we_id_sign_y2ks_20_years_after_the_new_millennium/

January 1, 2001

• https://www.netmeister.org/blog/epoch.html

September 9, 2001

• Unix Tick Tocks to a Billion

• https://en.m.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2001

• http://rachelbythebay.com/w/2024/02/07/feedback/

January 2, 2006

• This magic time is Monday, January 2, 15:04:05, 2006

May 13, 2006

• http://taint.org/2006/07/20/171844a.html

It sound like that could equate to “Sat May 13 02:27:28 BST 2006”, or 1147483648 seconds since epoch, which makes it exactly 1,000,000,000 seconds until expiry of 32 bit time. Coincidence? Seems too strange as to a computer that is not a nice round number.

March 28, 2007

• https://www.benshoof.org/blog/sierras-macintosh-timebomb
• https://en.m.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2007

firstDIVUWithA8C0Overflows = 2831155200

January 1 1904 (old Macintosh epoch) + firstDIVUWithA8C0Overflows = September 18 1993

September 18 1993 + 5000 days = May 28 2007

December 1, 2007

592 weeks before next GPS week rollover

• https://acurazine.com/forums/3g-tl-audio-bluetooth-electronics-navigation-94/navi-dash-clock-sync-megathread-update-all-should-fixed-now-630065/

June 14, 2008

…it means that 2008-06-14 23:29:20 UTC is, in a strange sense, “HTTP time”. If you see either that number or that date (with possible adjustments for your local time zone) showing up in your life inexplicably, this might just be why.

• http://rachelbythebay.com/w/2016/02/21/malloc/

December 31, 2008

The bug would be triggered on the last day of any leap year

• http://bit-player.org/2009/the-zune-bug

• https://lkml.org/lkml/2009/1/2/373

2010

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2010

• http://it.slashdot.org/story/10/01/06/0343252/Y201K

November 2010

• http://venturebeat.com/2010/11/01/iphone-daylight-savings-time-alarm-bug-plagues-users-in-europe-us/

• https://osxdaily.com/2010/11/06/the-iphone-daylight-savings-time-alarm-bug-and-how-to-fix-it/

December 12, 2010

434 weeks before next GPS week rollover

• https://www.furuno.co.jp/en/news/notice/notice_category.html?itemid=15&dispmid=965

2011

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2011

January 1, 2011

• http://www.macnn.com/articles/10/12/31/reports.of.alarm.issues.continue.to.plague.ios.4/

• http://www.macrumors.com/2010/12/31/iphone-clock-bug-prevents-alarm-triggers-after-new-years/

June 30, 2012

June 30, 2012 leap second

• http://arstechnica.com/business/2012/07/one-day-later-the-leap-second-v-the-internet-scorecard/

• http://blog.wpkg.org/2012/07/01/java-leap-second-bug-30-june-1-july-2012-fix/

• http://news.ycombinator.com/item?id=4188412

• http://serverfault.com/questions/403732/anyone-else-experiencing-high-rates-of-linux-server-crashes-today

• http://news.ycombinator.com/item?id=4182642

• http://www.reddit.com/r/programming/comments/y3mxv/clock_monotonic_avoiding_problems_with_leap/

• https://www.somebits.com/weblog/tech/bad/leap-second-2012.html

January 2013

• http://arstechnica.com/apple/2013/01/apple-says-do-not-disturb-scheduling-is-broken-until-january-7/

• http://arstechnica.com/apple/2013/01/ask-ars-why-will-apples-do-not-disturb-bug-fix-itself-next-week/

March 10, 2013

Daylight Saving Time begins on Sunday March 10, 2013

• http://www.nist.gov/pml/div688/grp40/wwvb.cfm

• http://blog.appliedis.com/2013/03/06/beware-daylight-saving-time-transitions-in-dot-net/

August 11, 2013

2^32 deci-seconds from January 1, 2000

• http://www.reddit.com/r/programming/comments/1mtsoy/nasa_officials_declared_the_deep_impact_mission/

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2013

ALSO 295 weeks before next GPS week rollover

• https://www.furuno.co.jp/en/news/notice/notice_category.html?itemid=55&dispmid=965

End of 2014

ISO week vs. Gregorian week

• https://www.theguardian.com/technology/2014/dec/29/twitter-2015-date-bug

January 1, 2016

• https://news.ycombinator.com/item?id=10825774

August 16, 2017

86 weeks before next GPS week rollover, but this is interesting because it is not EXACTLY on the week.

August 12 2017 is the actual point of 86 weeks before the next rollover.

So this issue is (86 weeks before the next rollover) + 4 days.

• https://jalopnik.com/hondas-and-acuras-from-1999-2004-had-their-clocks-fail-1798427017

October 6, 2018

• https://www.macrumors.com/2018/10/08/apple-watch-series-4-daylight-saving-time-bug/

October 21, 2018

GPS Week Number reached 1,000

• https://blog.fosketts.net/2019/04/06/gps-time-rollover-failures-keep-happening-but-theyre-almost-done/

• https://news.ycombinator.com/item?id=19593227

March 16-17, 2019

3 weeks before next GPS week rollover

• https://www.furuno.co.jp/en/news/notice/notice_category.html?itemid=753&dispmid=965

April 6, 2019

• https://en.wikipedia.org/wiki/GPS_Week_Number_Rollover

• https://twitter.com/ChinaAvReview/status/1114802018919411712

• https://en.m.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Second_GPS_rollover

April 30, 2019

• https://en.m.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Japanese_calendar_transition

November 2, 2019

30 weeks after last GPS week rollover

• http://rachelbythebay.com/w/2019/10/03/roll/

• https://news.ycombinator.com/item?id=21155040

• https://techship.com/news/gps-week-roll-over-issue-during-epoch-restart/

End of 2019

ISO week vs. Gregorian week

• https://www.reddit.com/r/videos/comments/ehnz3q/why_its_already_2020/

2020

Y2K20

• https://en.m.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Classic_Mac_OS

• https://twitter.com/jefposk/status/1213258774938415104

• https://twitter.com/nick_guerrera/status/1394435349980405762

• This Year’s Y2K20 Bug Came Directly From ‘A Lazy Fix’ to the Y2K Bug

• https://kotaku.com/due-to-a-y2k-like-bug-wwe-2k20-is-almost-unplayable-in-1840760479?utm_campaign=Socialflow_Kotaku_Twitter

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2020

February 29, 2020

2020 leap day bugs

• https://news.ycombinator.com/item?id=22452065

December 19-20, 2020

89 weeks after last GPS week rollover

• https://www.furuno.co.jp/en/news/notice/notice_category.html?itemid=753&dispmid=965

• https://acurazine.com/forums/3g-tl-audio-bluetooth-electronics-navigation-94/navi-dash-clock-sync-megathread-update-all-should-fixed-now-630065/

2021

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2021

June 20, 2021

115 weeks after last GPS week rollover

• https://www.furuno.co.jp/en/news/notice/notice_category.html?itemid=753&dispmid=965

October 23, 2021

• Watch out for GPS weirdness on October 23

• https://www.gps.gov/support/user/rollover/

January 1-2, 2022

143 weeks after last GPS week rollover

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2022

• Microsoft Exchange breaks on new year

• https://www.the-triton.com/2022/03/gps-week-number-rollover/

• https://panbo.com/2022-gps-rollovers-furuno-airmar-jrc-and-who-else/

• https://www.furuno.co.jp/en/news/notice/notice_category.html?itemid=753&dispmid=965

• https://news.ycombinator.com/item?id=29818572

• https://jalopnik.com/honda-clocks-are-stuck-20-years-in-the-past-and-this-mi-1848306970

May 14-15 2022

162 weeks after last GPS week rollover

• https://panbo.com/2022-gps-rollovers-furuno-airmar-jrc-and-who-else/

• http://www.jrc.co.jp/eng/about/news/2021/1224-1.html

September 17-18 2022

180 weeks after last GPS week rollover

• https://news.ycombinator.com/item?id=32700184

• https://sync.empowerednetworks.com/keep-your-ntp-server-current/

• https://www.orolia.com/will-your-network-time-servers-be-affected-by-the-september-2022-delayed-gps-rollover/

March ?, 2023

• https://panbo.com/2022-gps-rollovers-furuno-airmar-jrc-and-who-else/

February 29, 2024

Leap day

2025

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2025

2028

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2028

• http://rachelbythebay.com/w/2021/11/05/sevenbits/

• https://news.ycombinator.com/item?id=28828853

• https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=800627

• http://www.3kranger.com/HP3000/mpeix/en-mpe75/Beechglen2028/ch02s03.html

2032

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2032

February 7, 2036

January 1 1900 + 2^32 Second == February 7 2036

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2036

• http://rachelbythebay.com/w/2020/11/26/magic/

January 19, 2038

• https://en.wikipedia.org/wiki/Year_2038_problem

• https://linux.slashdot.org/story/19/03/05/1929233/linux-51-continues-the-years-long-effort-preparing-for-year-2038

With 32 bit signed integers, Unix time will overflow on: 03:14:08 UTC January 19, 2038

• http://lwn.net/Articles/643234/

• https://www.phoronix.com/scan.php?page=news_item&px=Linux-5.1-Year-2038-Syscalls

• Investigating why Steam started picking a random font

November 20, 2038

GPS Week rollover

February 6, 2040

old macintosh calendar expires

• https://apple.fandom.com/wiki/2040_date_limit

• https://lowendmac.com/lab/04/0115.html

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2040

September 18, 2042

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2042

2043

Microsoft Exchange update format

changing to unsigned long

• https://old.reddit.com/r/sysadmin/comments/rt91z6/exchange_2019_antimalware_bad_update/

January 19, 2048

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2048

2069

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2069

2079

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2079

2080

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2080

2100

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2100

2106

unsigned 32-bit count of seconds (also) since 1970

• https://news.ycombinator.com/item?id=22745295

With 2^5 = 32 bit unsigned integers, Unix time will overflow on: 06:28:16 UTC February 07, 2106

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2106

2108

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2108

2137

GPS 13-bit week rollover

• https://lobste.rs/s/tdalbi/gpsd_time_will_jump_back_1024_weeks_at

• https://www.gps.gov/support/user/rollover/

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2137

November 4, 2153

• http://rachelbythebay.com/w/2017/09/27/2153/

2232

• https://www.netmeister.org/blog/epoch.html

2262

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2262

April 4, 2262

2262-04-11 23:47:16 UTC is when a system with a signed 64 bit number to store Unix time shifted left with nanoseconds added to it runs out of time.

• http://rachelbythebay.com/w/2020/11/26/magic/

2286

• https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2286

July 21, 2554

2554-07-21 23:34:33 UTC is when the same scheme but with an unsigned 64 bit number runs out of time.

• http://rachelbythebay.com/w/2020/11/26/magic/

4000

• https://en.m.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Years_4000,_8000,_etc.

4147

• https://www.netmeister.org/blog/epoch.html

4501

• https://en.m.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_4501