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:

"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."

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.