(The morning has set in) and surely the beautiful and graceful daughter of Janaka fond of performing morning ablutions, shall come to this river of pure water to perform them. "Sandhyā literally means the point of time which connect day and night. It however, generally means the period after sunset and before the night sets. But here with reference to the speech which Hanumān began by the end of night, it means the morning.
संध्याकालमना: श्यामा ध्रुवमेष्यति जानकी। नदी चेमां शुभजलां संध्यार्थे वरवर्णिनी॥