Converters
Time Converter
Convert seconds, minutes, hours, days, weeks, and years.
Free to use — no sign-up or login.
One hour is 3600 seconds and one day is 86400 seconds. Ninety minutes is 1.5 hours. A week is 604800 seconds, seven of those days.
Calendar dates, such as adding months on a real calendar, belong on the date calculator. This page multiplies fixed lengths.
Fixed months and years
The month in this list is 30 days, 2592000 seconds. The year is 365 days, 31536000 seconds. Neither follows a calendar, a leap day, or a 28-day February.
Milliseconds
One millisecond is 0.001 seconds. Minutes are 60 seconds. There is no separate field for leftover minutes after an hour.
Worked example: 90 minutes
From minutes to hours, 90 displays as 1.5. From hours to seconds, 1 hour is 3600 s. A listed month is 30 days, not a calendar month.
\[ 90\,\mathrm{min}=1.5\,\mathrm{h} \]
Frequently asked questions
How many hours is 90 minutes?
1.5 hours.
How many seconds are in a day?
86400.
Is a month 30 days here?
Yes. The month factor is exactly 30 days.
Is a year 365.25 days?
No. The year factor is 365 days. Leap years are not averaged in.
Can this add 3 months to a date?
No. Use the date calculator for a calendar.
References
Assumptions and limitations
Months are 30 days and years are 365 days. This is not a calendar. Six significant digits on the result.