Negative rotation with time zone offset


I’m trying to make a reverse UTC lookup index for the UTC index in my watchface that works as a “decoder ring” to tell me what local-time hour corresponds to a given UTC-hour.

The gray is the local time wheel, it is supposed to rotate, but my tag-expression is not having any effect.

The tag expression I’m using: -[TMZN_OFS_WITH_DST]*15 (the math might be wrong, but that’s easy to check later).

This is what I want to happen if I am in, for example UTC-5, where local midnight is UTC 05:00

Is TMZN_OFS_WITH_DST not a numeric value or something? If so, can I parse it as a number to use it in tag-expressions that allow me to do math?

EDIT: I know that the numbers need to be counter-rotated to look good, but once I have the main rotation working, I’ll apply the opposite rotation to the numbers individually.


Are you want to rotate your gray index and watch hand altogether?

After reading your question I understand that you want to rotate your gray index based on your local time eg. UTC-5. But the difference of orange index and gray index should be always 5 so if you rotate the gray index then the orange index will be rotate also.

Almost, I want to rotate the gray based on the local time zone, not local time, but when I use the local offset nothing happens with the rotation.

Hi, @nyaray
Unfortunately, the [TMZN_OFS] and [TMZN_OFS_WITH_DST] provide a string result instead of number. That’s why nothing happens for the rotation.

One method you can try is using bitmap font. For example, you can prepare 24 gray wheel images for each degree, and map each image to each custom text such as “+1”, “+2” that [TMZN_OFS_WITH_DST] tag provides.

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Damn, what a shame. Thanks for your suggestion. I’ve already done so many hacky things to get my watch face working/looking how I want that I feel it’s no longer worth it, I’m just gonna leave it as is and program the thing using kotlin later.

Hello, maybe you can calculate it from the UTC timestamp. Maybe the formula needs some polishing.
I mean something like this in the rotation tags:

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Thank you! Clever mathemagics thinking there :slight_smile:

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