Question 1

What is ISO 8601 duration format?

Accepted Answer

ISO 8601 durations use the pattern P[n]Y[n]M[n]DT[n]H[n]M[n]S. Example: P1Y2M3DT4H5M6S = 1 year, 2 months, 3 days, 4 hours, 5 minutes, 6 seconds.

Question 2

How do you convert ISO 8601 to total seconds?

Accepted Answer

Parse each component and sum: (years * 31536000) + (months * 2592000) + (days * 86400) + (hours * 3600) + (minutes * 60) + seconds. Months and years are approximate (30.44 days/month, 365.25 days/year).

Question 3

Can I add or subtract two durations?

Accepted Answer

Yes. Enter two valid ISO 8601 durations and choose add or subtract. The result is shown as a new ISO 8601 duration and total seconds.

`P1Y`	1 year (365.25 days)	`P1M`	1 month (30.44 days)
`P1D`	1 day	`PT1H`	1 hour
`PT1M`	1 minute	`PT1S`	1 second
`P1Y2M3DT4H5M6S`	1y 2m 3d 4h 5min 6s
`P1DT12H`	1 day 12 hours

⏳ ISO 8601 Duration Calculator