I would like to be able to distinguish between zero as a value and a field that’s blank because I didn’t input data in it. I’m not always the most consistent about logging data, so I have a lot of 0s of all value types (except scale, I guess). But “I had zero alcohol drinks” is not the same as “I didn’t log anything,” you know? One is data, and one is lack of data. So this probably makes my correlations not particularly accurate. (And yes I would like to have 0:00 as data as an option even for time of day … I often want to log bedtime or meds taken time at midnight.)

To be clear, some attributes are “N/A” when you don’t enter any data. This is different to zero, so the two are indeed distinguishable. However, not all attributes default to N/A.

This is a tricky one because I totally get what you mean. Essentially we have to make a compromise between starting with N/A and thus not having any valid value when the user didn’t put in any data, and not asking users to explicitly enter a zero to track a valid zero value for an attribute. We’ve made the call to go with the latter, so that if you have 0 coffees or 0 time in a meeting, you don’t have to track it, because that’s the default. The downside being there’s no way to say “actually, no data for this day — it wasn’t zero, it was N/A because I don’t know, didn’t track it, etc”. We don’t have any plans to change this currently.

Also, 00:00 is already a valid time of day.