This American would use "did."
It's time I did / do my homework.
Could either word in bold be used? I have been told that Americans use 'do', while the British use 'did'.
Is this the case?
Thanks.
This American would use "did."
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
NOT A TEACHER
Take a look at this entry form Practical English Usage, p. 286:
It's "did" in both AmE and BrE.306 it's time
2 followed by past tense with present meaning
It's time can also be followed by a subject with a past tense verb. The meaning
is present.
It's time she went to bed. It's time you washed those trousers.
I'm getting tired. It's time we went home.
The expression It's high time ... is often used in this structure in British
English, to say that something is urgent.
It's high time you got a job.