@koffienl said:
@Harry-van-der-Wolf Can you point me to one of your projects with the time.h function?
Actually it is not my project but a minimally changed project from @okadesde where I replaced the DHT with a ds18b20 functionality. And I used the time function (here) which is based upon the default esp8266 repository. The same can be done for an initial year-date-time.
Something like
string InitDate = year() + mon() + day()