On Sat, 22 Jul 2017 08:45:31 -0500, Joel C. Ewing wrote: > >But arguing that the z-architecture clock format should support dates >prior to 1900 CE implies that storing date-time values in a >machine-specific time-stamp format would be desirable. > Doesn't the same argument apply to dates after 20167 CE? I hardly expect the hardware to go to that date, but why should software such as STCKCONV support less than the full potential range?
The fuzzy Julian-Gregorian boundary poses a problem. I believe Rexx ignores it; its date conversion functions presume a proleptcic Gregorian calendar. >Why would anyone ever choose to represent or store historical event time >stamps prior to 1900 CE using a date format that is vendor-specific and >even machine-architecture-specific, and with a resolution that is >totally inappropriate for historic events considering the accuracy of >clocks of those times? Machine-independent date-time formats are a much >wiser choice for long-term storage of historic time stamps, or as a >"universal" date-time format to use as an intermediate form when >converting between two other date-time formats. > How many digits for the year? Geologists routinely discuss 4500000000 BCE; astrophysicists 13700000000 BCE; cosmologists ponder 10**100 CE. Does this argue for a variable-length format? XML? Suitable for interchanve; not for data base internals. How does DB2 represent times internally? If TOD, a 25-year mortgage is already confronting a Y2.042K problem. I deplore "BP" (Before the present). Scientists who use it have no faith in the durability of their work. It's appropriate only in certain contexts, such as "Radiocarbon dating has limited accuracy earlier than 10,000 BP." -- gil > Joel C. Ewing > >-- >Joel C. Ewing, Bentonville, AR [email protected] > >---------------------------------------------------------------------- >For IBM-MAIN subscribe / signoff / archive access instructions, >send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
