UTC Orbit

UTC Orbit

by Dave Massey

2 ratings
2 reviews
Free

Details

  • Released
  • Updated
  • October 22, 2015
  • July 7, 2026

Features

UTC Orbit screenshot #1 for iPhone
UTC Orbit screenshot #2 for iPhone
iphone
ipad
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About

This utility converts between human-readable dates and a YYDDD.FFFFFF format essential for spacecraft orbital element calculations. It also features a UTC alarm clock based on the day of the year and a large digit UTC display.

UTC time conversion
YYDDD.FFFFFF format display
UTC alarm clock
Day of Year alarm setting
Large digit UTC clock display
Background alarm notifications
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What's New in UTC Orbit

2.3

July 7, 2026

Updated to iOS 26

User reviews

Excellent UTC and Day of Year Clock

Excellent and straight to the point!

Does what it says on the tin.

Nicely-written software with a decent interface. This App does one thing, and it does it well. I like this uncluttered and simple approach Thank-you.

If the screen-locking which is mentioned in the description could be removed, then I could rate the App with 5 stars.

At the moment, the first window opens with orientation such that the charger connector is at the bottom of the screen - no good at all when charging an iPad.

Worse still, when the full-screen clock opens, it is displayed in landscape, which is fine, except that it is inverted. My iPad stand places the charge connector and Home button on the left, which is fine for me; I'm left-handed. But a locked, inverted display is hopeless!

At least, if the display must be locked, can we have a choice of orientation, please?

Thank-you.

I'll still be using this App, and awaiting the next version. :-)
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Developer apps

FAQ

What is UTC Orbit used for?

UTC Orbit is a time conversion utility primarily for Earth orbital elements calculations for spacecraft. It also includes a UTC alarm clock and a large digit UTC display.

How does the YYDDD.FFFFFF format work in UTC Orbit?

This format displays time as YYDDD.FFFFFF, where YY is the two-digit year, DDD is the day of the year (000-366), and .FFFFFF is the decimal fraction of the day. This is standard for manipulating spacecraft tracking TLEs.

Can UTC Orbit be used as a regular alarm clock?

Yes, UTC Orbit features a UTC alarm clock based on the 'Day of Year'. You can set alarms using the pick wheels, and they will function in the background with sound and screen notifications if notifications are allowed.

Does UTC Orbit have ads?

No, UTC Orbit does not contain advertisements.

What devices does UTC Orbit support?

UTC Orbit is available for iPhone, iPad, and iPod.

How often is UTC Orbit updated?

The latest version, 2.2, was released on December 29, 2020. The app was initially released on October 22, 2015.

What is the age rating for UTC Orbit?

UTC Orbit has an age rating of 4+.

How do I switch between the calculation screen and the large digit clock in UTC Orbit?

On iPhone, rotating the device activates the large digit UTC clock. On iPad, touch 'UTC screen' to activate it. To return to the calculation screen, touch 'Back to main screen'.