30 days ago from today
The date below is 30 days back from whatever today is on your device, worked out when the page loaded. Nothing to type in, nothing sent anywhere.
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Working it out from your device’s clock…
The date above is calculated on your own device when the page opens, from your device’s clock and time zone. Nothing is uploaded and no date is stored on this page.
What 30 days means here
Your browser reads today’s date from your device and subtracts 30 days, which gives the date above. The same date engine drives the date calculator, so the two pages cannot disagree with each other.
Every calendar day counts, weekends and public holidays included. Today is treated as day zero, so the result is the 30th day before today rather than counting today itself as the first day. If your contract counts the starting day as day one, shift the result by a day.
Because the answer depends on today, it is not written into the page. It is recalculated every time the page opens, in your own time zone, and never leaves the device.
The start of a rolling month
Counting back thirty days gives the opening edge of a rolling month — the window used by "last 30 days" reports in analytics, card statements described as a thirty-day billing period, and eligibility rules phrased as "in the previous 30 days". Rolling is the operative word: unlike a calendar month, this edge moves forward every night, so a transaction that was inside the window yesterday can be outside it today.
Thirty days back in ageing and returns
Accounts-receivable ageing puts everything invoiced before this date into the 30-day bucket or older, which is usually where chasing begins. Retail return windows work the same way from the buyer's side: if a purchase pre-dates the date shown above, a thirty-day returns policy has already closed on it. Both are counted in calendar days, weekends included.
What the count does not skip
Nothing is skipped here: weekends and public holidays sit inside the count, which is what a plain day count means in almost every contract, notice and policy.
The result box still shows how the span divides — how many of the days are Mondays to Fridays and how many are weekend days — because that is usually the real question behind “will this be dealt with in time”. Public holidays are not deducted from that weekday figure.
Common questions
What date was 30 days ago? The box above shows it, computed from your device's clock when the page loaded, so it is correct on the day you read it.
Is 30 days ago the same as last month? No. Last month means the same date in the previous calendar month, which is 28 to 31 days back. A fixed 30-day count rarely matches it.
Do "last 30 days" reports include today? Usually they cover 30 days up to and including today — that is today plus the 29 days before it, so the earliest day included is the day after the date shown above.
Nearby counts
If this was not quite the interval you needed, one of these will be.