I don't think it would be acceptable to write:
If yesterday is Wednesday...
The time adverbial yesterday implies a past sense. We cannot (normally) talk about yesterday in the present tense.
There is an exception to this rule: sometimes the present is used (informally) to describe the past; often when a story is being told.
I was sat in the pub yesterday when this guy runs over and punches me!
Your original sentence can be explained as most zero-conditionals can: as expressing a sense of cause and effect, a general truth.