I've got about a dozen tomato plants of different varieties in containers on my northeast-facing deck (mid-Atlantic region of the US), which receives about 6 hours of direct sun exposure per day. Some of them have developed these black splotches on their leaves. Based on these articles on Southern Living and Old Farmer's Almanac, it looks like this might be a sign of Septoria leaf spot. Is that what this looks like to you all as well?

EDIT: Clarified orientation and daily sun exposure.