I want to talk about my summer schedule
school from 7/3, 7/4, 7/5 will be only in the morning
Now I want to make sentences
Is 's' necessary? Is the expression "in the mornig" a set phrase which doesn't need to be pluralized?
During 7/3, 7/4, 7/5, I will study in the mornings and go home in the afternoons
During 7/3, 7/4, 7/5, I will study in the morning and go home in the afternoon
Is time phrases usually not plural?
I don't think the "s" is necessary.
You are referring to the morning in general as a particular part of the day; there's no need to word it in a way which pays explicit reference to each particular morning (the plural version).