Advanced Date Time Calculator
This date and time calculator contains 5 main functions: calculates the result time by adding/subtracting some years, months, weeks, days, hours, minutes and seconds; calculates the differences (years, months, weeks, days, hours, etc.) between two times; counts the days of week, weekdays, weekends between two dates; Gets the conversion between various date time elements; Calculates UNIX date based on a large days/ number of seconds.
It also supports separators and decimals in all numeric fields.