subang ang bulan

Etymology
Literally, "the moon rises." The sense of "first quarter" may have been derived from observation of the moon seemingly rising again after "sinking" and staying below the horizon during the new moon. See.

Noun

 * 1)  first quarter; waxing crescent; between new moon and going into half-moon

Usage notes

 * The night after the new moon is referred to by multiple names, among which are "bag-ong subang" (newly risen), "buhi ang bulan" (resurrected moon), "bulhot sa punuan", and more systematically "unang subang (first subang)." The following nights up until the half-moon are thus designated accordingly by ordinal numbers; e.g. "ikaduhang subang", "ikatulong subang", ... "ikapitong subang".