[FIG(quote)[
[FIGCAPTION[
[1] [CITE@en[M Technology and MUMPS Language FAQ, Part 1/2]]
([TIME[2018-11-05 14:30:22 +09:00]])
<http://www.faqs.org/faqs/m-technology-faq/part1/>
]FIGCAPTION]

> In M, the current date and time is contained in a special system variable, 
> $H (for "HOROLOG").  The format is a pair of integers separated by a comma, 
> e.g. "54321,12345"  The first number is the number of days since December 
> 31st, 1840, i.e. day number 1 is January 1st, 1841; the second is the number 
> of seconds since midnight.
> But why 1841?  According to Steve Clay, sbc@pobox.com, the following 
> answer appeared in the "Just Ask!" column of the September 1993 issue of 
> "M Computing," a publication of the M Technology Association, Silver Spring, 
> MD 20903 (Phone: 301-431-4070), in the form of a letter from James M. 
> Poitras: 
> [SNIP[]]
> "When I decided on specifications for the date routine, I remembered reading 
> of the oldest (one of the oldest?) U.S. citizen, a Civil War veteran, who 
> was 121 years old at the time. Since I wanted to be able to represent dates 
> in a Julian-type form so that age could be easily calculated and to be able 
> to represent any birth date in the numeric range selected, I decided that a 
> starting date in the early 1840s would be 'safe.' Since my algorithm worked 
> most logically when every fourth year was a leap year, the first year was 
> taken as 1841. The zero point was then December 30, 1840... 
> "That's the origin of December 31, 1840 or January 1, 1841. I wasn't party 
> to the MDC negotiations, but I did explain the logic of my choice to members 
> of the Committee." 

]FIG]


[2] [CITE['''['''tz''']''' Epic fail for DST fallback in hospital health records]]
([TIME[2018-11-05 14:27:51 +09:00]])
<https://mm.icann.org/pipermail/tz/2018-November/027181.html>

[FIG(quote)[
[FIGCAPTION[
[3] [CITE[M Technology and MUMPS Language FAQ, Part 1/2]]
([TIME[2017-05-11 01:42:27 +09:00]])
<https://web.archive.org/web/20150828234407/http://www.vmth.ucdavis.edu:80/m/m_faq1.htm>
]FIGCAPTION]

> In M, the current date and time is contained in a special system variable, 
> $H (for "HOROLOG").  The format is a pair of integers separated by a comma, 
> e.g. "54321,12345"  The first number is the number of days since December 
> 31st, 1840, i.e. day number 1 is January 1st, 1841; the second is the number 
> of seconds since midnight.

]FIG]