Days, months and business days between dates, add or subtract durations, ISO week numbers and day of year, and DST-aware elapsed time between local times.

Date Calculator. Operations: diff — Difference between two dates in years/months/days, total days, weeks and business days. add — Add or subtract a duration ("1y 2m", "-90d", "P2W") or a number of business days. info — Weekday, day of year, ISO week, quarter and leap year for a date (plus Unix time of local midnight). elapsed — Exact elapsed time between two local date-times, following DST in each time zone.