If “yesterday” is at the beginning of the sentence, then a comma after yesterday is mandatory. ... Alternatively, if “yesterday” is in the middle of the sentence or is acting as a noun, then it should usually not be followed by a comma.

Where do you put yesterday in a sentence?

You use yesterday to refer to the day before today. She left yesterday. Yesterday she announced that she is quitting her job. Yesterday is also a noun.

Do you put comma after today?

If “today” is in the middle or at the end of the sentence, then a comma is not needed. ... However, if “today” comes at the beginning of the sentence as an introductory word, then it should be followed by a comma. Example: Today, we are going to finish our homework.