Timewarrior supports the following duration formats based on ISO-8601:
'P' [nn 'Y'] [nn 'M'] [nn 'D'] ['T' [nn 'H'] [nn 'M'] [nn 'S']] PnnW
P1Y 1 year P1.5M 1.5 months PT1S 1 second PT4.5H 4.5 hours PT4H30M 4.5 hours P600D 600 days P3W 3 weeks P1Y1DT1H1M1S 1 year and 25 hours, 61 seconds (imprecise term)
Note that the year and month terms are imprecise, being defined as 365d and 30d respectively. For precision use the other terms.
In addition to the standard duration formats, the following are supported:
<unit> is one of:
annual biannual bimonthly biweekly biyearly daily days, day, d fortnight hours, hour, hrs, hr, h minutes, minute, mins, min monthly, months, month, mnths, mths, mth, mos, mo, m quarterly, quarters, quarter, qrtrs, qtr, q semiannual sennight seconds, second, secs, sec, s weekdays weekly, weeks, week, wks, wk, w yearly, years, year, yrs, yr, y
1hour 60 minutes 1.5h 90 minutes 3mo 3 months 10d 10 days
Note that the year, quarter and month terms are imprecise, being defined as 365d, 91d and 30d respectively. For precision use the other terms.