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***** If you do not need the Non24-hr feature, use the Merlin24 watch face instead:</p><p></p><p>***** If you have problems with the app, please click "Contact Developer" before leaving a review.</p><p></p><p>--------------------</p><p></p><p>The Merlin watch face converts the standard 24-hr day into a custom Non24-hr day for individuals who experience Non-24-Hour Sleep-Wake Disorder with a circadian rhythm between 18-40 hrs (a.k.a. Non24). It is also useful if you have a friend or family member with Non24, or if you want a Non24-hr schedule for work productivity or other reasons.</p>

What’s New

v1.3.1, June 3, 2022:</p><p>- Fixed bug in weekday display</p><p></p><p>--------------------</p><p></p><p>v1.3.0, May 5, 2022:</p><p>Implemented changes recently made to Merlin24:</p><p>- Added option for white background</p><p>- Added option for color of steps bar after goal is reached</p><p>- Added option to remove leading zero in hours display</p><p>- Added option for heart rate in upper right (in place of notification count)</p>

Additional Information


This app requires access to:

  • Run in the background when it is not active (potentially affecting battery life)
  • Send/receive information to/from the Internet
  • GPS location
  • Heart rate, barometer, temperature, and altitude history
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  • fēnix® 7 fēnix® 7, quatix® 7
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  • fēnix® 7X fēnix® 7X, quatix® 7X – Solar Edition
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  • fēnix® Chronos fēnix® Chronos
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  • quatix® 6 quatix® 6
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  • Rey™ Rey™
  • tactix® 7 tactix® 7, tactix® 7 – Pro Ballistics Edition, tactix® 7 – Pro Edition
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  • vívoactive® 3 Music vívoactive® 3 Music
  • vívoactive® 4 vívoactive® 4, GarminActive
  • vívoactive® 4S vívoactive® 4S, GarminActive S
  • vívolife vívolife
Average Rating: (10 Ratings)

Zbořil Rostislav
December 10, 2021 | Version

Pleas 1 White background setting 2 more language (Czech) or numbers date format 1.1.2021 3 instruction for set date and time sync. Good job. I work 12h Day 2 Day, 2 Day free and 12hour 2 days in the night. This system helped me.

Developer Reply
December 10, 2021, catopuma

I’m so glad you are enjoying this watch face! Thank you for your compliments and feedback! I recently added language support and other updates for the Merlin24 watch face, and I will apply similar updates to Merlin in a few weeks after the holidays. But I did not add Czech, so thank you for requesting this language. I can also add the option for a white background. For instructions to set the date and time sync, please click “Contact Developer” and I can send this via email. The app description on the Garmin website has limited character space, and I cannot fit it there. In the future I will make a website with this information. I develop this watch face solo in my spare time. If you like, you may support me using the link in the app description. Thanks!

Bougie Clement
December 9, 2021 | Version

We can change the langage ? I would like to put french langage.

Developer Reply
December 9, 2021, catopuma

Hi, language support is coming soon. In the meantime, if you do not need the Non24-hour feature, you can use the Merlin24 app instead.

October 21, 2021 | Version

Why so many settings for the end user?

Developer Reply
October 21, 2021, catopuma

Hi Panos, this watch face is designed for users who experience Non-24-hour sleep-wake disorder (see app description). The settings are to accommodate a custom circadian rhythm. If you do not need these features, please use the Merlin24 watch face instead.

James Cuzella
October 14, 2021 | Version

First off: Thanks to the developer for creating a non-24 watch face! This is the only timekeeping watch I've found so far to help keep a semi-consistent schedule while free running. The watch face does exactly what I need it to do: display my circadian day clock time alongside the secondary earth clock time in my timezone. As a newly diagnosed person with non-24, there were a few hurdles to overcome in order to learn how to use this watch face. First, I needed to find my circadian day length based on sleep or actigraphy data. Thankfully, the Garmin vivoactive 4 tracks sleep and activity rather well, as long as I continually update my "Normal Bed Time" and "Normal Sleep Time" under "User Settings". Those watch settings can be updated to avoid most false positive sleep detection events. The formula for circadian day length is simple thanks to this Reddit thread: Once I charted my sleep data and calculated my circadian day length, it was simple to input the values into "Non24 circadian rhythm hours", and "Non24 circadian rhythm minutes" settings for the watch face. The next more difficult part was to find my "Sync Date". This is the date when the non-24 clock and earth clock will be in sync, and it takes a value accurate down to a minute. Trying to read this off the sleep chart was difficult at best. When I input the value, I found that the watch was not set correctly according to my currently observed day phase alignment. I ended up simply adjusting the Sync day, hours, and minutes settings manually up or down and checking how it affected the watch value. After fine-tuning these for a while, I finally got the non-24 clock value to sync up properly with my current circadian time relative to earth time. I'm hoping that my day length is accurate enough given that I had to round the fractional minutes up by one. I'll probably find out soon whether this keeps in sync with my circadian rhythm accurately enough.

Developer Reply
October 14, 2021, catopuma

Yay! I’m so glad you’re using this watch face! I agree that there are lots of settings to keep track of, and I’m sure there is plenty of room for improvement. I’ve been wanting to make a website that describes all the features and suggested uses, and you are motivating me to do it. You are the first person I am aware of who is using this for Non24, and I would be glad to continue to get your feedback for improvement. Feel free to to click “Contact Developer” and provide your email address for direct correspondence.

Albert Ters
December 14, 2020 | Version 1.1.2

I woke up today and the watch is wrong! 2 hours ahead the normal !

Developer Reply
December 15, 2020, catopuma

Hi, please make sure you are using "24 hr" for the primary clock in the settings. To change the settings, click on the "Settings" button for this watch face in the Connect IQ app. Go to "My Device" then "Watch Faces". Please note that this watch face is designed to change the time of day for people who experience Non24-hr sleep-wake disorder, so the 2-hr difference when you woke up is probably because the "28 hr" clock was selected. Within the next couple of days I will upload a different app, Merlin24, which does not have the Non24-hr feature. In the future, if you have problems, please use the "Contact Developer" link before posting a review. Thanks