So my question is just rephrasing the other. Referring to your example, I understand that I can use -10 if I wanted a set time as the value, but I'd like to find the difference between 05:00 and 04:50 (-10 minutes); or the difference between 15:00 and 05:00 (-10 hours). I saw that Henrik had added it to the Feature requests originally but I cannot find that functionality. If this feature cannot be implemented, do you have a workaround I could use?