ezdatetime

A C++ library and console program that parses (ISO 8601) datetime strings (with timezone) into quickly sortable values (and back to strings) and allows arithmetic with various calendars and units. Calendars supported are No Leap, Gregorian, All Leap, 360 Days, Julian, and Proleptic. For arithmetic, units allow offsets and deltas in years, months, days, hours, minutes, and seconds, so datetimes can be computed relative to a baseline using an offset (a technique often used in scientific datasets such as NetCDF climate models). The library is a single header file with no dependencies.