http://tg-tj.facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion/business/help/190490051321426
For example, if you run an ad set Sunday to Tuesday with a daily budget of $10, then switch it to $20 at 12am on Wednesday, we'll switch from aiming to spend $70 over 7 days, to $80 over 4 days (the amount of days left in a calendar week when you changed your budget). Note that the actual amount spent from Sunday to Tuesday does not affect what we'll aim to spend Wednesday through Saturday.