I wanted to say "Stores are closed at least until April, 13th", and speaking with two different Japanese people I had two different answers: one said that 「せめて四月の十三日まで」 was right, the other said that it sounds odd and 「少なくとも四月の十三日まで」 would be better.
I found that they differ in strenght/emotion, but if that's the only difference both of them would be right depending on how the speaker feels about the stores being closed.
I tried to do a bit of research, and it seems that 「せめて」 is more linked to wanting/asking at least a certain quantity of something, like 「せめて一度は日本に行きたい」, but I'm not sure if it can or not be used in the opening sentence.