Add a month to a date without drifting
Adding 30 days looks right until it lands on the 2nd of the wrong month. This is the trap behind every subscription date.
The data
| Row number | A | B | C |
|---|---|---|---|
| 1 | Customer | Signed | Renews |
| 2 | Novak Ltd | 2026-01-31 | |
| 3 | Rossi GmbH | 2026-03-15 | |
| 4 | Silva SA | 2026-05-30 |
Your task
Put a formula in C2 that returns the date one month after the signing date in B2.
Your formula goes in C2
The checker compares your formula against the accepted answers — it does not run it. The expected result is shown with the solution so you can verify it in your own spreadsheet.
Why this is the right formula
B2 is 31 January, and there is no 31 February — so EDATE clamps to the 28th. Adding 30 days instead gives 2 March, which puts the renewal in the wrong month and drifts further with every cycle. That clamping is the whole reason EDATE exists rather than being a plus sign.
Try next
Practise it on a full dataset
Free to use, share and republish — including commercially. Attribution isn't required, but it's what keeps these free to make, and there's one ready to paste below.
Questions
Does this actually run my formula?
The checker normalises case, spaces, argument separators and dollar-sign anchors, then compares your formula with a reviewed list of accepted answers. It does not evaluate the formula. Copy the data into your spreadsheet to verify the expected result independently.
Can a correct formula be rejected?
Yes. The accepted list includes several reviewed approaches, but cannot recognise every equivalent formula. Compare an unlisted solution with the expected result in your spreadsheet and use the page feedback if an accepted answer is missing.
Do I need an account?
No. There is no signup, no progress tracking and nothing stored — everything happens in your browser.