Months to Time Converter

One month here is the mean Gregorian month: 30.436875 days, or a twelfth of the 365.2425-day mean year. That is 730.485 hours, 43,829.1 minutes, and 2,629,746 seconds. It is an average, so no real calendar month matches it — February holds 672 hours and July 744.

Seconds, minutes, hours, days, and weeks are fixed units; a month is not. So the conversion needs a convention before it can return any number at all, and the one used here has a name. UCUM, the standard code for units of measure, defines the mean Gregorian month as one twelfth of the mean Gregorian year, and that year is 365.2425 days — the figure the US Naval Observatory gives for the Gregorian calendar once its four-hundred-year leap rule is averaged out. A twelfth of 365.2425 is 30.436875, and the division leaves no remainder, so the month length is exact rather than rounded. Everything else follows from definitions: 24 hours a day, 1,440 minutes, 86,400 seconds, seven days a week, twelve months a year. One month therefore comes to 730.485 hours, 43,829.1 minutes and 2,629,746 seconds, and twelve months return exactly 365.2425 days. What this cannot do is name a real span. A 28-day February holds 672 hours and a 31-day July 744, so the average lands between them and matches neither. Nor does the converter know today's date: it multiplies a number you type, and the answer never depends on which month you meant or which year it sits in. For the exact distance between two dates, count days instead. The field accepts 0 to 1,200 months, a hundred years, with two decimals, and solves backwards if you enter a duration.