Cash withdrawals from ATMs may be made as often as you like. You may withdraw up to $500 (if there are sufficient funds in your account) per business day. Maximum withdrawal, per transaction, is $300. So, a $500 withdrawal must be completed in two transactions.
For purposes of determining whether you have reached the daily limit, a day ends at midnight. Friday, Saturday, and Sunday are considered as one business day for the purposes of this limit.