I thought that St.Andrews Novena started today but I just learned it started yesterday. Does this mean that I can’t do the Novena/it doesn’t count?
Just do it. Don’t worry about it “counting.”
When you miss a novena day, just say it twice the next day and carry on.
Ask God to please backdate the missed prayer to the proper day.
I miss days all the time in novenas and stuff, especially the longer ones that go 33 days and 54 days. It’s nigh impossible for me to be perfect and never miss a day when it goes that long.