ISO_WEEK1_WDAY    379 maint/gnulib/lib/nstrftime.c           - (yday - wday + ISO_WEEK1_WDAY + big_enough_multiple_of_7) % 7
ISO_WEEK1_WDAY    380 maint/gnulib/lib/nstrftime.c           + ISO_WEEK1_WDAY - ISO_WEEK_START_WDAY);