275. Davening Too Early

Tefillah u’Birkas Kohanim 3:7

If a person davens before the proper time, he does not fulfill his obligation and must daven again at the proper time. If circumstances force a person to daven shacharis after dawn (but still before its proper time), he does fulfill his obligation. One may daven maariv for Shabbos on Friday before sunset. Similarly, one may daven maariv for Saturday night while it is still Shabbos. Since maariv was not originally instituted as an obligatory prayer, we are not as concerned about its time. Nevertheless, Shema must be recited at its proper time, which is after the stars appear.

Tefillah u’Birkas Kohanim 3:8

If one intentionally allowed the proper time for davening to go by, he cannot make up the lost prayer service. If it happened unintentionally, one can make up the missed prayer at the next service. One first davens the regularly-scheduled prayer, followed by his compensatory prayer.