Date Time Calc is an application to calculate future and past dates adding a date interval and to calculate date difference between two assigned date
It is realised for business and technical user who are in need of calculation of date in a bullet proof way.

Do you want to know the future date adding 150 days from today?
Do you want to know the difference in years, months, days between 25 March 2009 and today?
Date Time Calc can do it in one click.
All using the Mac standard date-time controls you already know.

Date Time Calc is absolutely easy to use because it uses 'natural' elements to compute dates (by popular demand from the user of the old release) and it was re-written to use the latest algorithms provided by Cocoa on date computations
You can add or subtract to dates, years, months, days or work with absolute precision and add or subtract days, hours , minutes and seconds to guess future and past date-times.

You can also calculate difference between two dates using calendar specification (years, months and days) or using a time precision method specifying date and time and obtaining a difference in days, hours, minutes and seconds.

Date Time Calc has no calculation buttons, adjusting date and time in two elements instantly update the result in the remaining third element.
Simply and natural as any application has to be, you will be amazed using it!

Any time you calc a date or a difference the result is also displayed in textual form on the bottom of the window.
At any time you can save the result in the log (persistent over re-launch)

Date format are expressed in accordance with your preference country settings.

Result can also be copied to the clipboard in textual format
example (some european country format selected in system pref):
3 Jun 2018 + ( 120 days ) = 1 Oct 2018

if you use also time, the string will show it (USA format selected in system pref)
example: Jun 3, 2018 at 11:01:33 AM + ( 150 days ) = Oct 31, 2018 at 11:01:33 AM
The log can collect and save all the calculation you need to record using a command button
At any time you can clean the log resetting it.

Requires macOS 10.10 or successive (optimized for macOS 10.13 High Sierra)

• Results displayed and updated as you type
• Uses 'natural' elements to compute dates (years, months, days, hours, minutes, seconds)
• Uses 'natural' elements also to compute differences (years, months, days, hours, minutes, seconds)
• Date display using your current local settings and language
• 'Set date to now' button for fast calculation of backward and forward dates from the current date
• Calculates time difference, if requested, also using hours, minutes, seconds
• Calculates time interval, if requested, also using hours, minutes, seconds
• It can add or also subtract time
• Result summarised also in a plain text to avoid misinterpretation
• The result can be sent to the log, saved over re-launch
• Log can be reset at any time
• Bullet proof results using macOS Apple libraries to calculate and manipulate dates

PDF user guide embedded in the app and accessible via the Help menu

What's New

Version 2.2.1

• Bug fix
• Various Optimizations

Ratings and Reviews

Programmers Point of View


Much as the other reviewer before me stated, I really like this app. I bought version 1 (also on store) and use it daily. The one complaint I had in version 1 - I found to have in Version 2. Did I pay more, yes - but when it fits a need, its worth it. I find myself having to calculate time differences very often and this app makes doing that simple for me. The log was a cool twist and something I can see myself using a lot.

All in all, this is very user friendly and I hope the developer(s) continue to enhance this more. While buying newer versions makes sense on big releases, I hope some of those modifications happen in this version and not force loyal customers to buying every new change. (Nickel and diming kills reputations). The changes between version 1 and 2 justify the added cost though so I cant complain. Thanks for a great app.

Awesome Date And Time Calculator!


This date and time calculator has a small footprint and works like it’s suppose to. I have tried many other similar apps that fell short of their basic functionality. Date And Time Calc 2 works like a charm. Thank you.

Needs to provide both business and calandar days

Big Mac 007

App would be a lot more useful to me if it provided both calandar and business days.


Tension Software s.a.s.
1.8 MB
Age Rating
Rated 4+
© 2011-2018 Tension Software


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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