A new version of the GNU C compiler's file c-common.c is available: ftp://elsie.nci.nih.gov/pub/c-common.c This version does strftime format checking against the formats recognized by an impending release of GNU's strftime.c; as suggested by Paul Eggert, it's also been retooled to minimize the differences between it and the stock c-common.c (at the cost of a bit of obscureness). Also available is ftp://elsie.nci.nih.gov/pub/strftime.c which is a first attempt at run-time strftime format checking. If the environment variable CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS is defined, strftime formats are checked at run time and diagnostics are written to stderr about formats that produce two-digit years in all locales, in the current locale, or in some locales. And a year-2000 related question: might it be best to change strftime so that "%x" yields, for example, 1996-08-22 rather than 08/22/96 as is currently true? Feedback on the new files and the question most welcome! --ado