Until When Can One Recite Tikkun Chatzot?

Shavua Tov. One may recite Tikkun Rachel until dawn. Ideally, it is best to say Tikkun Leah before dawn; however, it is permitted to say it even afterward, as they are merely psalms of Tehillim.

Sources: Yalkut Yosef Part 1 (Siman 1, Section 49).

Blessings, Hillel Meirs