I've recently learned that the future tense should rarely be used in a "when" or other clause indicating the future, but I know that there are exceptions to almost every grammatical rule; therefore, I have a few examples an am wondering if anyone can tell me if these would be correct or incorrect and why. I realize some of these could be stated in a more economical or practical manner, but I'm just speaking technically.

Saturday is when I will fix the faucet. (sounds correct to me)

According to my understanding of the rule this sentence should be -

Saturday is when I fix the faucet.

This sounds like I fix the faucet every Saturday, which doesn't make any sense unless my faucet is very consistently broken.

6:00 is when I will finish my homework. (sounds correct to me)

Again according to me understanding, this should be -

6:00 is when I finish my homework.

This sounds like 6:00 is my regularly scheduled time to do my homework, which could be true, but would completely change the meaning of the sentence.

Any thoughts?
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Comments  (Page 2) 
As far as I know, ' when' is used like " if-clause". Never use 'when+future in the subordinate clause. Instead, 'will' is possible in the main clause.
For me the sentence ' Yesterday is when I will...." In this particular example, 'When' is the pronoun relative that replaces " Yesterday"
I think my explanations are clear!