1)
What is "mil'Ma'ale he'Chares"?
1.
Rashi: It is before sunset, when the sun still appears high. 1
2.
Radak #1: Mil'Ma'ale refer to cessation (of the sun to shine), like "ka'Alos Gadish b'Ito" (Iyov 5:26; it is cut in its time). Alternatively, it is still seen in the sky; it did not enter below the ground.
3.
Radak #2: It is when the sun rises; he pursued them the entire night, and returned in the morning.
4.
Malbim: He returned due to the sun rising in the morning. He had few men, and could fight only at night.