I want to put a week number at the start of bits of text I create. Is it as simple %numberdate% / 7?
The simple answer is
The complicated answer is that there are several ways to define the week of the year, so there could be some confusion if you're trying to communicate with someone else.
ISO 8601 offers a formalisation of one approach, but it takes the view that weeks start on Monday – an assumption that doesn't work everywhere.
I never did say thanks. For my purposes this is perfect. I just needed the week number at the front of my weekly review notes so that they sort correctly inside TheBrain.
See this topic for a deeper discussion Week Number One Ahead of Actual Week - #14 by tjluoma