If you approve time entries in BillQuick and then generate a bill for a client, but you don't want to bill the client for the current billing period, what happens in the next billing period?
If you skip billing for the current billing period, unbilled time and expenses are available to you in the next billing period as long as you select the correct date range in the Period From/To fields in the Billing Review screen. 
If you have a situation where you are holding time or expenses to be billed later, it is recommended to use the 'As Of' Period option in Billing Review. This will ensure that you are not missing any unbilled time and expenses from the previous billing periods.