We need Monday to moan.
The days of the week were not named after the planets but the activities ascribed to them -
Monday - moan day, back at work we moan
Tuesday - The T should obviously be a Y giving You 'as day. As in You 'as to larf.
Wednesday - Wouldn't day. As in Wouldn't it be nice if it was the weekend
Thursday- Theres day. Theres got to be more to life than this
Friday - Freeday . Freedom from toil comes on Friday night.
Saturday - its got to be obvious. What did you do? Sat about.
Sunday - So now day. So now thats over I've got to go back to work tomorrow.