Want to have blank date cells yield weekday results AFTER I ENTER in a new date

Hi- I'm pretty 'new' to excel Home & Student 2019. I have created a small table to track card game results and calculate winning percentages of different players. I was struggling with how to handle cells where I had not yet put in a new game date, and having 'blank' for the day-of-week appear if no date entered. I discovered the "IS BLANK" statement on Google, and Bob is my father's brother! I'm attaching my sheet for possible use by new players. I also have special formula language if a player has 'never' won a game, to eliminate error messages for divide by zero problems in winning percentage section. Hope this helps other 'newbies' (like me).
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