Opening the iTunes Store.If iTunes doesn't open, click the iTunes application icon in your Dock or on your Windows desktop.Progress Indicator
Opening the iBooks Store.If iBooks doesn't open, click the iBooks app in your Dock.Progress Indicator

iTunes is the world's easiest way to organize and add to your digital media collection.

We are unable to find iTunes on your computer. To buy and download Julian Date Calculator by CosmoWerx, get iTunes now.

Already have iTunes? Click I Have iTunes to open it now.

I Have iTunes Free Download
iTunes for Mac + PC

Julian Date Calculator

By CosmoWerx

Open iTunes to buy and download apps.


The Julian Date Calculator gives the user a simple and quick way to convert between Coordinated Universal Time (UTC) in the Gregorian Calendar to the Julian Date as well as the following selection of additional epochs and time systems:

- Modified Julian Date
- Reduced Julian Date
- Truncated Julian Date (NIST and NASA)
- Dublin Julian Day
- Lilian Day Number
- ANSI Date
- Rata Die
- Unix Time
- GPS Time

The Julian date (JD) is the number of days and fractions of a day since noon January 1, 4713 BC at Greenwich. The Modified Julian Date (MJD) has an offset of 2,400,000.5 days from the Julian Date and hence starts at midnight November 17, 1858. The Julian Date is often used for scientific time measurement by the astronomy community and was introduced to provide a single system of dates that could be used when working with different calendars.

What's New in Version 1.5

Added GPS Time. The GPS Time represents the number of seconds since the GPS epoch 00:00 UTC (midnight) on January 6, 1980. GPS time is not adjusted and therefore is offset from UTC by an integer number of seconds, due to the insertion of leap seconds. The number remains constant until the next leap second occurs.

iPhone Screenshot

iPhone Screenshot 1

Customer Reviews

Works very well on iPhone5

It would be perfect for me if it would have three more functions:
- Display a third UTC seconds "wheel"
- Allow entry and display of GPS time in hexadecimal notation
- display current leap-seconds. That display could display number in effect when displaying historical time, or disappear when not displaying current time.
With those changes it would be worth more than $0.99 to me.

Julian Date Calculator
View In iTunes
  • $0.99
  • Category: Utilities
  • Updated:
  • Version: 1.5
  • Size: 0.4 MB
  • Language: English
  • Seller:

Compatibility: Requires iOS 4.3 or later. Compatible with iPhone, iPad, and iPod touch.

Customer Ratings

We have not received enough ratings to display an average for the current version of this application.