the ninth day of the fourth month

This is the fourth month of the Hebrew calendar. The ninth day is near the end of June on Western calendars. This is during the dry season when there is very little or no rain. (See: rc://en/ta/man/jit/translate-ordinal and rc://en/ta/man/jit/translate-hebrewmonths)

the people of the land

These are the inhabitants of Jerusalem, including refugees from the surrounding villages that fled to Jerusalem when the war started.