datetimeformat in a file name

[KateC]

TOSTRING(DATETIMEFORMAT(DATETIMENOW(),-1, "MONTHS","%B %Y"

I want to save a file that is produced on the first business day with the previous month appended to the end. So on June 1 the file should be saved as "Excel File May 2021".  I'm getting a parse error so I've got something out of order here in my expression. Probably the -1, "months" in datetimeformat?  It can't be difficult to do this but I still struggle with these kinds of expressions. Looking for suggestions. Thanks!

[Luke_C · Accepted solution]

Hi @KateC 

Try adding a datetimeadd to your formula, the below seems to return "May 2021"

TOSTRING(DATETIMEFORMAT(datetimeadd(DATETIMENOW(),-1, "MONTHS"),"%B %Y"))

[KateC]

That's exactly what I wanted. Thank you!