Duration Formatter

1. Type a duration in any supported form: P1DT2H30M15S, 5415, 90000 ms, 01:30:00, 1h 30m or 2 hours and 15 minutes.
2. Read the result table. The ISO 8601 form, a normalized ISO form, long and short human text, hh:mm:ss, and totals in seconds, milliseconds, minutes, hours and days are all shown together.
3. Copy the row you need. Each output has its own Copy button.

These values do not depend on the date or time zone, so they are the same wherever you open the page.

#An ISO 8601 duration

Input P1DT2H30M15S — one day, two hours, thirty minutes and fifteen seconds:

#Seconds to hours and minutes

Input 5415 (a video length or a job runtime in seconds):

#Normalizing an overflowing duration

Input PT90M. ISO 8601 allows 90 minutes; the normalized form carries them into hours:

#Months are approximate

Input P1M. A month has no fixed length, so totals use the average Gregorian month and a notice says so: "Years and months vary in length; totals use average lengths (365.2425 days, 30.44 days)."

The Duration Formatter is a form, so it has no settings drawer. These are the parts of the page:

• Duration input — accepts ISO 8601 (P1Y2M3W4DT5H6M7S, including decimals such as PT1.5H and a leading minus), bare numbers as seconds, numbers with ms as milliseconds, hh:mm:ss or mm:ss clock values, and unit phrases (3d 4h, 2.5h, 45s, 2 hours and 15 minutes).
• ISO 8601 and ISO 8601 (normalized) — the duration as written, and re-expressed in days, hours, minutes and seconds.
• Human and Short — "1 hour, 30 minutes" and "1h 30m". Where the browser supports Intl.DurationFormat, it is used for the wording.
• hh:mm:ss — clock notation; hours are not wrapped at 24, so a day and a half is 36:00:00.
• Totals — the whole span in seconds, milliseconds, minutes, hours and days.

#"Couldn't read this duration"

The input matches none of the supported forms. Try PT1H30M, 5400, 01:30:00 or 1h 30m. A lone P or PT with no parts is not a duration, and neither is text with units the parser does not know.

#1:30 became 90 seconds

Two-part clock values are read as minutes and seconds, like a track length. For one hour thirty minutes, write 1:30:00, PT1H30M or 1h 30m.

#PT1M versus P1M

Without the T, M means months. P1M is about 30.44 days; PT1M is 60 seconds. This is a frequent mistake when writing durations by hand.

#Negative durations

A duration like -PT45M keeps its sign in every row: ISO (-PT45M), clock (-00:45:00), totals (-2700), and the Human and Short rows ("−45 minutes", "−45m"). The word rows use the typographic minus sign U+2212, so if you paste them into code or a spreadsheet that expects a hyphen-minus, take the ISO or totals row instead.

#Totals for years look slightly off

A year is counted as 365.2425 days and a month as 30.44 days on average. For exact calendar arithmetic — adding one month to 31 January — use date functions in your language, not a fixed number of seconds.

#What does PT1H30M mean?

It is an ISO 8601 duration: P starts the period, T starts the time part, and 1H30M means one hour and thirty minutes — 5,400 seconds. The format is used by YouTube's API, Schema.org metadata, iCalendar, Java's Duration, .NET's XmlConvert and many JSON APIs.

#How do I convert seconds to hours, minutes and seconds?

Type the number of seconds. 5415 shows as 01:30:15, "1 hour, 30 minutes, 15 seconds" and PT1H30M15S. In code, hours are Math.floor(s / 3600), minutes Math.floor(s % 3600 / 60) and seconds s % 60.

#How do I convert milliseconds to minutes?

Type the value followed by ms, such as 90000 ms. The table shows 1.5 total minutes, "1 minute, 30 seconds" and PT1M30S. Without the ms suffix, a bare number is read as seconds.

#How do I parse ISO 8601 durations in code?

Java has Duration.parse("PT1H30M") for time-based durations and Period.parse for date-based ones. Python's standard library has no parser; the isodate package provides parse_duration. In JavaScript, Temporal.Duration.from("PT1H30M") is available where Temporal is supported. Months and years need a reference date to become an exact number of seconds.

#Why does P1D not always equal 24 hours?

In calendar arithmetic, a day can be 23 or 25 hours when a time zone changes to or from daylight saving time, so P1D added to a date keeps the wall-clock time. This formatter measures spans in fixed units, counting a day as 86,400 seconds, which is what timers and video lengths need.

#Is my input sent anywhere?

No. Parsing and formatting happen in your browser inside an isolated frame that blocks network requests, and nothing is stored unless you turn on "Remember my last input".

M means months before T and minutes after it: P1M is a month, PT1M a minute. ISO 8601 explained covers intervals and the rest of the standard.

Convert a single instant with the Unix Timestamp Converter, format it with the Date Formatter, or express it as "in 3 days" with the Relative Time Formatter. All date tools are in Date & Number.