at the time
prep. phr..prep. phr.. This phrase refers to a particular moment in the past that you are talking about.
prep. phr.. A temporal adverbial phrase referring to a specific, contextually understood point in the past.
At the time, I didn't understand the problem.
I thought it was a good idea at the time, but I see now that I was wrong.
The technology seemed revolutionary at the time, though it was quickly superseded by more efficient systems.
This phrase is typically used to contrast a past situation or feeling with the present.
Contrast with 'at that time' (more emphatic and specific) and 'at this time' (refers to the present moment, more formal than 'now').
In the time, we lived in a small apartment.At the time, we lived in a small apartment.The correct preposition for this fixed temporal phrase is 'at', not 'in'.