Open Source Date Calculators

A simple command to convert calendar dates to julian dates. Quite useful in timing situations where you need elapsed time between dates. Also useful for astronomy applications.

Tarikh component is prepared to convert solar date to Gregorian and vice versa and is able to provide the most accurate result in date conversion. Delphi Version (12)

The Assignment Calculator breaks down research and writing projects into manageable steps based on your due date. Each step includes hints and "how-to" links to additional resources. You can also email or print a reminder outlining each step.

Breaks down the research process into pre-defined steps. Users enter a start date and end date for an assignment and the Assignment Calculator will compute the dates s/he needs to complete each step. Written by the University of Minnesota Libraries.

Canyon is a date calculator utility that aims to provide handy methods to perform arithmetic calculations on java.util.Date objects. Developers are free to plug in their own localized instances of java.util.Calendar or to use the default GregorianCalenda

Joda-time based utility Java class that allows calculation related to downtimes. You set a list of downtimes (date-time intervals), and the calculator will give you the ending date-time of a duration, and uptime between two points in time, too.

Easter Calculator for Mobile Phone J2ME compliant. You can calculate the date for several years or you can verify if one date is an Easter holiday or not.

http://github.com/Appendium/objectlabkit A set of modules to handle common financial functions. The first module is Date Calculator which handles holidays and weekends. A set of rules are implemented to deal with days falling on a holiday: Forward, Backward, Modified Forward, Modified Backward New FX Rate Calculators

Perfect Age calculator is a free-ware tool to calculate age by a given date of birth. It tells age in years and also includes the months in the result box so that you will know when your next birthday is. This tool is very useful for official use like office, schools, institutes etc.

This calculator will allow you to convert between many different world calendar schemes and calculate ranges and ages based on these calendars. The calculator also has a script language that allows you to create variations of the built-in calendars: calendars that shift the new year to a different day, hybrid calendars that switch between schemes, local observational calendars that depend on a particular location, year counts that change for specific eras (regnal calendars) and calendars that require adjustment due to subtle differences in calculation.

Goal of this project is, creating a calculator that can handle all date and time operations that a user may need. You can operate with milliseconds as months, years or dates. Examples: 2013-11-25 + 3d => 2013-11-28 2013-11-25 - 2013-10-20 => 36d 1h 5h + 6h => 11h 1382220000t => 2013-10-20

This software has four major modes- Simple, Scientific, Base & Equation. It also has Unit Converter, Date Calculator & Prime Number Generator.

Working Days Calculator is a Windows desktop tool that calculates the number of working days between two dates in Belgium or the Netherlands, leaving out Sundays and holidays. The tool also provides the possibility to compute the total cost of the result. So you don't need to open a seperate calculator to compute it. It's primarily intended for people working in the newspaper industry, as most newspapers are printed on a daily basis, except on Sundays or official holidays. The size of the program is comparable to that of Calculator, included in all versions of Windows. It's written in C#. The UI is in WinForms. The targetted framework is .NET 3.5, so you can use it on Windows XP and higher.

This program calculates the days, months and years between two dates. This is a console based version compiled for windows. GUI version and linux compatibility soon!

Two full-fledged object-oriented classes dealing with dates (class cDate) and spans of time (class cPeriod) written in C++. The datecalc-cpp project is a sub-project of tbvs-hr (https://sourceforge.net/projects/tbvs-hr).

Two full-fledged classes dealing with dates (class cDate) and spans of time class cPeriod) written in PHP. The datecalc project is a sub-project of tbvs (http://sourceforge.net/projects/tbvs).

Hail Eris! What better way to show your devotion to the Goddess of Chaos and Discord herself than to show the Discordian Date wherever and whenever you would show a mundane date?

There are times you want to check how old you are (in years, months, days) or how long you need to wait for the next flash sale... pdd (python3 date diff) is a small cmdline utility to calculate date and time difference. If no program arguments are specified it shows the current date, time and timezone.