graham@DRCVAX.ARPA (02/12/88)
Many have asked this question before. As far as I know, there isn't an easy, or difficult way to add or subtract times and dates from DCL. The VAX stores dates and times in a quadword format. Basically, the quadword is the number of 100 millisecond chunks since midnight, 17 November 1858. (Don't ask!) It would be simplicity itself to write a brief FORTRAN program to subtract dates so you could have file age. You need the use of three system services/RTL routines: 1. SYS$BINTIM to translate the date strings into quadword format 2. LIB$SUBX to subtract the two quadwords 3. SYS$ASCTIM to convert the resulting quadword into a string Remember that delta times use negative values. hope this helps a little, Dan Graham ------
dave@wsccs.UUCP (Dave E Martin "VAX Headroom") (03/02/88)
In article <8802152352.AA08946@ucbvax.Berkeley.EDU>, graham@DRCVAX.ARPA writes: > quadword is the number of 100 millisecond chunks since midnight, 17 > November 1858. (Don't ask!) This was the time when the current calendar was accepted for use. +-----------------------------------------------------------------------------+ | | Dave E Martin | DISCLAIMER: Been Cancelled | | /\ | "...between the streets of | $ opinion/mine/noUinTech | | / \ . /\ | Dallas, and the beaches of |----------------------------| | / \/ \/\/ \ | Miami ... THIS was Max | ...!ihnp4!utah-cs!utah-gr! | | / U i n T e c h \ | Headroom's finest hour." | uplherc!sp7040!obie! | | | --Max Headroom | wsccs!net23.dnet!dave | +-----------------------------------------------------------------------------+
tsf@arizona.edu (Ted Frohling @ CCIT-Telcommunications, University of Arizona) (03/08/88)
In article <231@wsccs.UUCP>, dave@wsccs.UUCP (Dave E Martin "VAX Headroom") writes: > This was the time when the current calendar was accepted for use. What? That date just happens to be the Julian day 2000000 (have I got the right number of zeros?). It does not have anything with acceptance of any calendar by anyone. Just a convenient demarcation point. -- Ted Frohling Internet: tsf@rvax.ccit.arizona.edu Network Support BITNET: tsf@arizrvax.BITNET CCIT - Telecommunications AT&T: (602) 621-4834 University of Arizona, Tucson, AZ 85721
dave@wsccs.UUCP (Dave E Martin "VAX Headroom") (03/15/88)
In article <4174@megaron.arizona.edu>, tsf@arizona.edu (Ted Frohling @ CCIT-Telcommunications, University of Arizona) writes: > In article <231@wsccs.UUCP>, dave@wsccs.UUCP (Dave E Martin "VAX Headroom") > writes: > > This was the time when the current calendar was accepted for use. > > What? That date just happens to be the Julian day 2000000 (have I got the > right number of zeros?). It does not have anything with acceptance of any > calendar by anyone. Just a convenient demarcation point. I remember reading somewhere that it was the calendar. However, in looking in _VAX/VMS Internals and Data Structures_ (ver 3 edition) ch 11.1.2 page 215: "The system time is defined by a quadword value measuring the number of 100-nanosecond intervals since 00:00 hours, November 17, 1858 (the time base for the Smithsonian Institution astronomical calendar)." Which, of course, is probably based on the above mentioned julian day. +-----------------------------------------------------------------------------+ | | Dave E Martin | DISCLAIMER: Been Cancelled | | /\ | "...between the streets of | $ opinion/mine/noUinTech | | / \ . /\ | Dallas, and the beaches of |----------------------------| | / \/ \/\/ \ | Miami ... THIS was Max | ...!ihnp4!utah-cs!utah-gr! | | / U i n T e c h \ | Headroom's finest hour." | uplherc!sp7040!obie! | | | --Max Headroom | wsccs!net23.dnet!dave | +-----------------------------------------------------------------------------+