I am trying to get the current hour of the day using date: "%H" in a set variables widget. I do the this first on day of month (date: "%d") which works okay, but the hour doesn't appear to return any value, any suggestions?
Basically, trying to compensate for the time difference in UK and US, using 'now'.

From your screenshot I can see one use of
%Hin which you set atime_zonevariable to{{ 'now' | date: " %H %M " }}. I can then see you are comparing thattime_zonevariable as a time.When you compare as a time in Studio you need to provide the time in the form "HH:MM", but it seems you have it in the format " HH MM ".
Try setting the variable to be
{{ 'now' | date: "%H:%M" }}and see if things work.