Silver Week only occurs when there's a coincidence of holidays in certain days, one always happens on the third Monday of September (the respect for the Aged Day) and the other needs to fall on Wednesday (Autumnal Equinox Day, which usually happens on Sept. 23) to create the string of off-duty days, Saturday and Sunday are default break days and Tuesday is a bridge between the other ones thus being an addtional free day. The next Silver week will happen in 2020.
If the amiibos doesn't arrive by mid October, I'll cancel and ask a refund.
Goodnight!