[dewd]

I've been thinking about this but my trying-to-get-over-flu brain is not getting anywhere with it.

Let's say I have a group of tags.

And I want to be able to see when I first added any one of those tags to a particular book, and, if possible, to search by that date, or sort by that date. I do not want the date to change if I add another one of those tags later - so from the first time it's set, it should be "frozen".

I had two ideas (but am open to better solutions):
1. use a custom column built from other columns which would, when one of those tags is added, autofill with the current date (but I'm a novice at templates - the ones I use, I've copied from here - so I'd need help building that)
2. use Action Chains, which I already use to add those tags, so it would be straightforward to add another action to fill in the date on a date column.

In either case, though, I don't know how to tell it to not change after it's filled the first time - i.e. if I later add a second one of those tags.

Thanks in advance, and apologies if I'm still more addled than I thought and this isn't making sense.