minor, adapt __get_jan01_wday() condition on whether to fix up the 28y equiv
minor, adapt __get_jan01_wday() condition on whether to fix up the 28y equiv

Signed-off-by: Sebastian Freundt <1f0829204b3475c52f714f96be4e7b39a87b6e74@ga-group.nl>

rudimeier/dateutils,rudimeier/dateutils,rudimeier/dateutils