Calculate time_t correctly from (day, month, year): 1/1/70 is 0, not 1.
Calculate time_t correctly from (day, month, year): 1/1/70 is 0, not 1.

ok deraadt@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars