I just found that I want to write almost exactly the same reply as I did 1 year ago.
1 day for 5 red packs, 2 day for 9, 3 day for 12, 4 day for 14, >5day for 15.
If you are new, you need to test and try. Trust me there is a confirmation screen for this.
There are Also some guides for new users in this forum that you can read.
Welcome to ask, but suggest to check before questioning if other's advice is correct.