What I meant was that if I have an 'arrive by' date, I have 'permission' to start organizing boxes that day to get them out. If its a send-by date, then it's ambiguous and users may get upset if I send out boxes before their seeds have arrived. It leaves the host open to criticism for doing it 'too early'.
Since everyone said early on that it's important to have seeds back by the end of January because that's when many southerners do their planting, I'm trying hard to ensure that happens.
[Edited to change two typos]
