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Date & Time Calculator for iPhone, iPad, Mac & Android

Find the exact time between two dates, add or subtract time from a date, and see the phase of the moon for any day.

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Free with ads · In-app purchase unlocks the full Pro Premium version

Calc Pro Date & Time Calculator - Screenshot 1
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Date & Time Calculator Features

Time between dates

Find the exact interval between two dates and times, in days, hours, minutes and seconds.

Add or subtract time

Add or subtract days, hours, minutes and seconds from a date to find a deadline or due date.

Lunar moon phases

See the phase of the moon for your start and end dates.

Day and week numbers

See the day of the week, day of the year and week number for any date.

Tape View

Results go to the tape so you can copy or e-mail them.

Great for

  • Project deadlines
  • Countdowns to events
  • Ages and anniversaries
  • Stargazing and night photography
Read the step-by-step Date & Time Calculator guide

Frequently Asked Questions

How do I count the days between two dates?

Set the start and end dates and times, then tap Calc. Calc Pro shows the interval in days, hours, minutes and seconds.

Does Calc Pro show moon phases?

Yes. The Date & Time Calculator shows the lunar moon phase for your start and end dates.

Is Calc Pro free?

Calc Pro is a free download for iPhone and iPad on the App Store and for Android on Google Play and the Galaxy Store, supported by ads. The Pro Premium in-app purchase unlocks the full version, including crypto rates, PDF export, and the newest financial worksheets, unit categories, constants and statistics tools. The Mac app has no ads: it starts with a free 7-day trial of everything, then needs Pro Premium.

Is Calc Pro available on Android?

Yes. Calc Pro is available on Google Play for Android phones and tablets, and on the Galaxy Store for Samsung Galaxy devices.

Is Calc Pro available on Mac?

Yes. Calc Pro for Mac is on the Mac App Store. It has no ads and starts with a free 7-day trial of every feature. After that, Pro Premium unlocks it. It's the same one-time purchase as on iPhone and iPad, so if you've already bought Pro Premium there, restore it on your Mac at no extra cost.

More in Calc Pro

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See everything in Calc Pro

Download Calc Pro

Calc Pro combines 10 powerful calculators with 23 financial worksheets. It's the trusted choice of students, professionals, and investors worldwide, and the only app that can truly replace your pocket calculator. Now with support for iPhone Duo.

Download Calc Pro for iPhone & iPadDownload Calc Pro for MacDownload Calc Pro for Samsung GalaxyDownload Calc Pro for Android

Free with ads · In-app purchase unlocks the full Pro Premium version

Or use the Date & Time Calculator free in your browser