Bank transfer deposits (via ACH) typically clear in 4 - 5 business days.
Bran transfer requests initiated on Gemini are processed at 5pm ET Monday - Friday at 24-hour intervals. Any deposit you initiate by 5pm ET will be processed and submitted to your bank that same day. Any deposit you initiate after 5pm ET will be submitted to your bank at 5pm ET the following business day.
For example, if you initiate a bank transfer deposit at 6pm ET on Thursday, the deposit will not be submitted to your bank until 5pm ET on Friday (assuming Friday is not a holiday). As a result, your deposit will fully clear between Wednesday (at the earliest) and Friday (at the latest) of the following week. If, however, your deposit was instead initiated at 4pm ET on Thursday, then it would have fully cleared between Tuesday (at the earliest) and Thursday (at the latest) of the following week. As you can tell from this example, the timing of when you initiate your bank transfer deposit impacts the speed at which it fully clears and is credited to your account.