The fastest your bank could possibly show a charge I make to it right now is tomorrow. Most will take longer than that. If it's near a weekend, it could take 3 or more calendar days. The authorization can show up immediately, the charge cannot.
Authorizations happen in real-time over the card networks. Settlements, where the charges get recorded and the funds actually move, happen in daily batches (or even less often).
In the meantime, customers assume they have paid for something, because they see it in the pending charges or holds list, whether funds were captured or not. Again, refer to previous comments on why that makes authorizing cards for the full amount of preorders problematic.