Hi everyone,
On the topic of the 'Day List', which all of us old-timers kept before eBird was a thing, I have a few recommendations! (ok, maybe I don't count as an old-timer but I've been at this birding thing for over 2 decades now!)
eBird as a scientific database values precise locations, with short sampling durations. Ideally, everyone would submit 5-min or 10-min point counts everywhere they go, but that isn't how birders work. That's why there's other protocols, like 'traveling' and 'incidental'.
If you wish to have a day list made for you, eBird can do that by amalgamating and calculating out all of your lists for any given day (just use 'Summarize My Observations' on the My eBird tab, and use the 'weekly' format). This is their way of getting around the old 'day list'.
If that doesn't work for you, and you wish to submit a single checklist for your whole day of birding with notes on where you went (unless you spent the whole day at a single location of course! or a very confined area), please do so at the County or Province level. This is easy to do under 'Submit a Checklist' - 'Select an entire County/State/Province'. eBird does not want these checklists in the database, and by entering at the County or Province level they will be automatically invalidated. They still stay in your personal lists, and they will still be available to researchers who wish to use them! By doing this you will be saving Jake, Dominic and I (or other reviewers in other locations) a massive headache of having to dig through the database to find these lists.
I should also specify that this is more important for modern lists. If you're submitting old lists from pre-1980ish, the discrete locale data will likely be missing and you may only have day lists to work with. This is fine, as long as they're in reasonably small areas, due to the lack of data from pre-eBird days.