One month ago — the standard look-back. Last month's bills, last month's reviews.
Type any number to find that date.
Thirty days ago is the standard look-back. It's the cycle bills run on, the cycle most reports cover, and the cycle most subscriptions renew on. When somebody says 'last month,' they usually mean about 30 days back, regardless of what calendar month it is.
Thirty days is when the picture starts to firm up. You can see what trended in your spending, your weight, your sleep, your mood. Anything shorter is noise. Thirty days is the smallest window where averages start to mean something. It's also the cycle the modern world runs on. Credit-card statements. Phone bills. Salary in many countries. Free trials. Net-30 invoices. The 30-day look-back is the default review cycle for almost everything that has a cycle.
Credit-card cycles, utility bills, and most subscription renewals run on 30-day cycles. Last month's charges = roughly 30 days ago.
If you sent an invoice 30 days ago, payment is due now. If you received one 30 days ago, your accounting team should be processing it today.
Whole30, Dry January, and other 30-day commitments hit their finish line exactly 30 days from the start. If you started one a month ago, you're at the end.
Most analytics dashboards default to a 30-day rolling window because it's long enough to smooth out noise but short enough to react to.
A month back is the unit at which life events become reportable. The trip you took. The book you finished. The argument that's now resolved. By the time you can describe an event as 'last month,' it's been processed enough to fit into a sentence. Thirty days is the smallest window where memory stops being raw and starts being narrative.
Here's the corresponding date for each of the days around today:
| Reference | Reference date | −30 days |
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