[WTHR_IS_DAY] and "IS_DAY"

Watch Face Studio
1

Does [WTHR_IS_DAY] work?
When I try it piut it always returns 1.
Even if I try ([WTHR_IS_DAY]) this does not make any sense.
But on the watch itself it runs fine as opposite to forecasthours (x, “IS_DAY”) because this one always returns 1 even on the watch

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2

Could you provide a sample project? If possible, including some images would also be helpful for better understanding and reproducing the issue.

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3

Do you see the switch in WFS to switch between Day and Night for testing .

4

I’ve seen the switch but it doesn’t make any difference.
I include mybwatch face (actually zipped, not just a rename of the extension)

  • 3 rings on the outside for the battery state shifting from green (100%) to red (0%)
  • at the top a largebox complication with an app shortcut for the weather
  • under the weather the clock (hours, colon, minutes)
  • under the clock three forecasts
  • on the left for the actual time + 6 hour
  • in the middle for the actual time + 12 hours, this also ghives problems because on the watch it never show a weather state, it is always unknown, in the preview irt is ok
  • on the right for the next day
  • all three of them show an icon and the time or the day
  • below these states I have
  • WTHR_IS_DAY, the text and the actual value
  • forecasthours (1, “IS_DAY”), text and value
  • for those two values it never change sin the preview , the WTHR_IS_DAY works on the watch itself, I’ve been playing around with the number of hours but it always shows 1
  • at the bottomn the battery percentage

WFF Coloured.zip (1.8 MB)

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5

I will have a lok but I will say It is a little beyond me . I do not think [WTHR_IS_DAY] works by the hour it just toggles at sunrise and sunset . I a not sure what you want to do with it . If you want to use it to show night weather Icons that has been covered . It can be used in a conditional statement to select Night Icons or whatever you want to do with the change of Realtime daylight .

6

I understand that [WTHR_DAY] represents the weather conditions for the day. While it doesn’t work in the preview, it functions correctly on the watch, so I’m okay with that.

However, my main issue is with the forecastHours() function — specifically, the IS_DAY parameter. This parameter doesn’t seem to work in the preview or on the actual watch.

My Setup:

  • I’ve configured forecasts for:
    • Current time +6 hours
    • Current time +12 hours
    • Next day (typically during the day)

The next day’s forecast works fine and shows the expected daytime weather conditions — no issues there.

The Problem:

The forecasts for +6 and +12 hours can fall either during the day or the night, depending on the current time. This is where the problem arises.

I want to:

  • Use the IS_DAY parameter to determine whether a forecast is for day or night.
  • Based on that, I would show or hide different weather icons (e.g. sun vs moon) or text fields accordingly.

But currently:

  • The IS_DAY check doesn’t seem to return anything meaningful, the return value is always 1 (or true)
  • It’s not working in either the preview or on the watch.

What I’m Trying to Achieve:

  • If the forecasted time is daytime, show day icons/text.
  • If it’s nighttime, show night icons/text.
  • Use IS_DAY as the conditional trigger to handle this logic.

I hope this makes my issue and intended solution clear.

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7

As you call it IS_DAY is the current Condition Day or Night . It can not be used in any Forecast .

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8

:camera_with_flash: Screenshot Reference

I’ve added a screenshot of the forecastHours function.
You can see the IS_DAY parameter there, which returns:

  • 1 if the specified forecast time is during the day

  • 0 if it is at night

image
image978×812 24.8 KB

:sun_with_face::crescent_moon: Displaying Day/Night Text Fields

If you use two text fields (one above the other):

  • One with a daytime bitmap font

  • One with a nighttime bitmap font

You can use the IS_DAY value to show or hide the correct text field.
This is done by using it in the opaque attribute of the color field.

:sun_behind_rain_cloud: Handling Unreliable Weather Data

Because weather data can be unreliable, I already use a workaround to show/hide my forecast icons.

Example:

I use forecastHours(12, 'COND') to show the condition icon for 12 hours ahead.
In the editor, it works fine, but on the actual watch, it always displays “unknown.”

So instead, I use this function to control the icon visibility based on whether weather data is available:

100 + ((forecastHours(12, 'IS_AVAIL')) - 1) * 100

  • When IS_AVAIL = 1 → result = 100 → fully visible

  • When IS_AVAIL = 0 → result = 0 → fully hidden

:last_quarter_moon: Using the Same Logic for Day/Night Icons

You can apply the same principle to show or hide your day/night icons using:

100 + ((forecastHours(12, 'IS_DAY')) - 1) * 100

This will:

  • Show the icon during the day

  • Hide it at night (or vice versa, depending on how you assign it)

:red_question_mark: Question

Does anyone know how to fix the issue where:

forecastHours(12, 'COND')

always shows “unknown” on the watch, even though it works in the preview?

1 Like
9

OK . Sorry @deboopi . What you are doing is way beyond me . All the best .