Shema

Hi,

There is a mitzvah to recite Shema twice a day. The Torah says to recite Shema "when we rise and when we go to sleep," and these times are talmudically understood to refer to the normal times of rising and going to sleep. Thus we are instructed to recite Shema (1) from first light through the first quarter of the day, and (2) from when the stars emerge, through the night.

Please note that this is separate from the mitzvah of reciting Shema before one goes to sleep. That is a practice for personal protection, as we have a verse-based tradition that reciting Shema protects us during the night. However, one could recite the entire Shema before going to sleep and so fulfill the mitzvah of reciting Shema in the evening, and reciting it at bedtime, simultaneously.

(Talmud, Berachot 5a)

Have a great day,
Mordechai