I try to use the moon phase tags, but when I move the date, nothing happens…how can I solve it?
I did something like:

([MOON_PO]>=13.5) + ([MOON_PO]<=14.5)?-100:0

+ is an or so the expression is always true.
You want
([MOON_PO]<=13.5) + ([MOON_PO]>=14.5) ? -100 : 0
Then it will show at full moon, or change it to ? 0: -100 to be blank at full moon.

Jakia wrote a Great Tutorial on using Tag expressions and while it is for GWS and those tags it holds true for WFS too.

Samsung Developer Relations


hi what is tag for new moon ? ([MOON_PO]<=27.5) + ([MOON_PO]>=6.5) ? -100 : 0 i tried this but not working @joaonunofazenda

Start with 0 opacity and
([MOON_PO]>=27.5) + ([MOON_PO]<=0.5) ? 100 : 0
shows the one day there is a new moon
or start with 100 opacity and
([MOON_PO]>=27.5) + ([MOON_PO]<=0.5) ? -100 : 0
Shows just for every day accept the one day that a is new moon

In the tutorial Jakia used 6.5 for New Moon position because she only had 4 images and included the Evening Crescent as part of the new moon image.

Remember to see this in action you can only see it happen in the preview (run) window and by changing days.

Samsung Developer Relations

It worked after putting this TAG ([MOON_PO]>=27.5) + ([MOON_PO]<=6.5) ? 100 : 0