16:2 Very early on the first day of the week, at sunrise, they went to the tomb (καὶ λίαν πρωῒ τῇ μιᾷ τῶν σαββάτων ἔρχονται ἐπὶ τὸ μνημεῖον ἀνατείλαντος τοῦ ἡλίου). In typical fashion, Mark uses a dual temporal expression, “very early … at sunrise” (cf. 1:35; 2:20; 4:35; 10:30; 13:24; 14:12, 43; 15:42). This one is seen as problematic by some commentators, since “very early” (λίαν πρωῒ) suggests the time before dawn, but the sun apparently has already risen (ἀνατείλαντος τοῦ ἡλίου). John 20:1 explicitly says Mary Magdalene went to the tomb “while it was still dark.” But this problem is more imagined than real. Mark’s expression clearly means an early hour, yet light enough for the women to see. Whether the sun has yet crept over the horizon is moot.
Strauss, M. L. (2014). Mark. (C. E. Arnold, Ed.) (pp. 717–718). Grand Rapids, MI: Zondervan.