PLEASE allow users to save a custom format in the Format Cells dialogue
I constantly need to use the format 'yyyy-mm-dd' and I have to type it in over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over.
Please, please, please, please, for the love of all that is good in this world, make a way to save custom formatting so it can be reused.
Craig Stokes commented
When you need to have dates in an format that sorts when saved as text, this is that format.
It does. Scroll to the bottom of the Custom formats list and yours will be there along with any other Custom number formats you used in that spreadsheet. Ones you don't want there, maybe experiments perhaps, can be deleted so only the needed additions show.
They are not then available from spreadsheet to spreadsheet, but creating 30 new ones a day and having to type it 30 times does not sound like the many "and over" instances you are talking about so it seems like this'd solve that.
Be nice if that list of added Custom formats was kept outside the spreadsheets, in Options somewhere, so it could then be available to all spreadsheets, new or old.
(I bet that's the source of the lack too: each added format gets a childish label like "34" which causes no problems so long as it's only in that spreadsheet and no other. Do a list outside the individual spreadsheets though and Excel could encounter on sheet where "34" is a bare time and another gets opened in which "34" was used for a 6-decimal number with "horse" added to the end. Cause no end of trouble. But they could overcome most of that if they did it like this but "jumped a level" on the childish labeling so they ensured uniquness and hence no conflicts.)