..........and seek what Allah Hath ordained for you, and eat and drink, until the white thread of dawn appear to you distinct from its black thread; then complete your fast Till the night appears; but do not associate with your wives while ye are in retreat in the mosques. Those are Limits (set by) Allah. Approach not nigh thereto. Thus doth Allah make clear His Signs to men: that they may learn self-restraint.
Surah Al - Baqara, Verse 187 (2:187)