BT BM 30b(51) :בקדמיתא ובחשכתא‏ : at dawn and at dusk
See the entire entry for ḥaškā, ḥaškəṯā n.f. dusk

BT BM 30b(51)var. :בקדמ<י>תא ובחשכתא‏ :
See the entire entry for qdmh#2 n.f. early state; dawn