Time Converter

The Time Converter switches between time units: milliseconds, seconds, minutes, hours, days, weeks, and the long units — months and years — which trip up every converter because they have no fixed length.

For planning and scheduling, most tools need exact answers: how many seconds in 3.5 hours (12,600), how many hours in a work week (168 minus time off), how many days in 6 weeks (42). For months and years the converter uses the standard average conventions — a month as 30.4375 days (the Julian year divided by 12) and a year as 365.25 days (Julian) — which is what most software and scientific contexts assume. For date-specific spans like 'March to September', the Date & Time calculators are the right tool instead.

Everything converts locally in your browser, from tiny millisecond counts to spans of decades.