Microsoft CRM 4.0 workflow Wait condition?

Hey i want to make a workflow that waits until a certain time to do something. For example. i want it to wait until 10 AM to send an email, or possibly have a window in which it woluld send the emails. for example: send an email if it is between 10 AM and 4PM. and if the workflow is triggered at 5 PM it would wait until the next day to execute.

thanks.