My co-worker tonight has stumped me. We're trying to find out the title and author of a short story in which the main character (male) lives his life in a non-linear way. He'll wake up one day and be in his thirties, the next he's a child, etc. He starts leaving himself notes so he knows what's going on during whatever time period in which he wakes up.
It's a science-fiction story, and the title is something like, "If This Is [day of the week], You Must Be [woman's name]".
The quote/title has been taken and reused so many times that Google has been useless. Ditto Wikiquote/Wikipedia.
Does anyone know what the name/author of this story?