Gemara:

Berachot 

Halacha:

Beit HaKenesset,  Tefillah 

Holidays:

Rosh Chodesh 

Collections: R' Grunstein 100 Blessing a Day

References: Berachot: 27B  

Description

Do you say יעלה ויבוא at an early Maariv on Erev Rosh Chodesh, even though the sun is still shinning outside? If so, why?