19 Jul
2025
19 Jul
'25
3:34 p.m.
Royce Williams <royce(a)techsolvency.com> writes:
I don't doubt the validity, but I'm looking
for other "citation
worthy" sources that supplement this claim --- ideally that predate
the ESR ones, so that they are unambiguously independent.
You can see the early history of the Jargon File through the SAIL copy,
which is AIWORD.RF in this directory:
https://www.saildart.org/[UP,DOC]/
The FLAG DAY entry was added between 1977-02-01 and 1977-03-11, and
initially read:
| FLAG DAY [from a bit of Multics history involving a change in the
| ASCII character set originally scheduled for June 14, 1966]
| n. A software change which is neither forward nor backward
| compatible, and which is costly to make and costly to revert.
| "Can we install that without causing a flag day for all users?"
That appears to be the earliest instance of the term in the public
SAILDART files. The next I could see is in a mail message from Mark
Crispin on 1977-10-01. (He must have liked the term; in the utzoo Usenet
archive, quite a lot of the early examples are from him too!)
--
Adam Sampson <ats(a)offog.org> <http://offog.org/>