19 Jan
2015
19 Jan
'15
11:28 p.m.
From: Peter Coghlan
Sent: Monday, January 19, 2015 4:24 AM
[failing to cite the previous posters, Mark Longridge and Johnny Bilquist]
ML:
>> After trying to get Unix v5 to understand
dates beyond the year 2000 I
>> had to wonder if any of the older operating systems from the 1970s or
>> older could do this.
>> So, did any operating system programmers from
this time period have
>> the foresight to use 4 digits for the year? I just checked APL/360 and
>> it seems that it does not.
JB:
> TOPS-20? VMS?
It was very near the end of the 1970s but VMS made a
really good effort to
handle times and dates well from the beginning.
Borrowing from TOPS-20 in the process, in spite of the VMS NIH mandate^Whabit.
The areas where I think it could have been done better
still are to have
stored the time internally in UTC rather than local time while
displaying local time and to have chosen an earlier base date than 17
November 1858.
The use of the modified Julian date (2,400,000.5 dates less than the
Julian date) dates to 1957, when the Smithsonian Astronomical Observatory
adopted it to track Sputnik in 18 bits on a 36-bit IBM computer. (Julian
dates, being used by astronomers, begin and end at noon rather than midnight.)
Rich
Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134
mailto:RichA at LivingComputerMuseum.org
http://www.LivingComputerMuseum.org/