The Ultimate Date Calculator is an industrial-strength date calculator designed and written by a lawyer for commercial, government & professional environments and is also suitable for home use.

It includes a number of different tools, stores all calculations to disk and presents them in alternate report formats that include paper, web page, RTF, CSV and SYLK files. It stores multiple calculations in a table so all of calculations can go into a single report. You have the option of excluding weekends and holidays.

It uses a combination of tabs and wizards to guide the user through each calculation, and has extensive context-sensitive help, while the Start page provides an easy departure point for novice users.

The Interval tool calculates the difference between dates, while the Math tool adds/subtracts any number of days, months and years to/from another date.

The perpetual calendar displays a calendar for any month of any year, and the Multiple tool calculates the number of days, weeks and years between a series of events.

The Repeat tool finds all recurring dates such as loan repayment dates, and collates them into a unified list.

The Chronology tool is designed for serious use by lawyers and other professionals. It has many options for describing dates, including 'approx.', 'June-July 97' etc and even sorts dates and times that cross time zones.

The Plan tool calculates any number of steps/events that occur a number of days months or years before or after one or more reference points and lets you design custom rich text format reports that incorporate the plan.

The Pro-Rata tool splits an amount, such as an electricity bill, between a number of different parties based on time and usage, then displays detailed calculations that will satisfy each party.

Finally, there is a Birthdays tool that instantly shows each person's current age and zodiac sign, a tool for converting Julian Dates, and a tab for recording notes.