I noticed that banks seem to fail on Fridays. Every bank failure in 2008  failed on a Friday.
It gives the regulators a chance to take over the institution over the weekend so it’s back to business on Monday.
On the Friday of a typical takeover, the FDIC arrives on-site with a large team to manage the transition. (When a large bank fails, this might include upward of 100 people.) The team has two main priorities. First, it must figure out which customers’ deposits are insured and which are not. This can be a tangle, since customers can sock away money in a variety of accounts to ensure that their deposits fall under FDIC-insured limits. The second priority is getting the bank ready to open under new ownership by Monday. That involves discarding any material with the old bank’s name on it—like posters, cashiers’ checks, and marquee signs—and putting the new bank’s paperwork, advertisements, and employees in place. Specialists from other departments, such as facilities, human resources, IT, public relations, and accounting, round out the FDIC’s team. Officials once even hired a hypnotist to help a bank employee remember a vault code.