Last week, your challenge was to help a user who entered a numeric value, but Excel displayed a date. I thought I’d really stump you this time, but Hometoy was the first to suggest the most common reason this happens—the user inserted a column. When inserting a column, Excel uses the formats from the column to the left. The figure is the clue; there’s a date column to the left.
Users can’t avoid this formatting behavior when inserting a column. Knowing what to expect can prevent anxiety and calls to you, but the solution is to apply the appropriate formats after inserting the column.
Shriks and Rudi-S discussed a similar situation when using formulas. If a formula refers to a date, the result will be formatted as a date. The challenge’s example doesn’t use a formula, but Shriks and Rudi-S are right.
In addition, Ppg mentioned a possibility that I hadn’t considered: if the user copied or entered a date first, Excel assumes a date format, even if the user deletes the date value and enters a numeric value. Nice catch Ppg!
Thanks to all of you for enhancing the conversation with these possibilities.