Sure, English has a future tense. It's not synthetically constructed, as are the present and the simple past, but that doesn't make it any less of a tense. I think we are confusing superficial construction here with deep meaning.
I agree with the grammar folks who say English in fact has a total of six tenses: the past perfect, simple past, present, present continuous, future and future perfect.
And as for Bingley's example "It's time we were going" I submit that "were" in that phrase is not in the past tense, it is in the subjunctive mood. As it were