office365 - Auto-updating PowerPoint Slides with previous Month and Year

Question

Background -
I have a PowerPoint presentation for a report I need to produce each month, that is reporting on the previous month's data. E.g. when I distribute the presentation in January 2021, it should have a date on each slide (positioning varies per slide), which references 'December 2020'.

Question -
In PowerPoint, is there a way I can have a text box that dynamically displays the previous month and (if applicable) the previous year? E.g., in January 2021, it will show December 2020 etc.

What I've tried -
I have tried using the 'Header/Footer' function and 'Date & Time' option in PowerPoint, but alas it doesn't seem to support previous dates.

question from:https://stackoverflow.com/questions/65874864/auto-updating-powerpoint-slides-with-previous-month-and-year

Answer 1

I was able to achieve this (albeit in a messy way) by creating a formula in an Excel file, then bringing this into PowerPoint as a linked image.