You can specify the time for daily e-mail notifications and the day for weekly e-mail notifications. Defaults are AM 00:00 and Monday respectively. The global settings are used for all users who have not specified an e-mail frequency in their own account yet (View notifications > Change your notification settings).
Prerequisite
You have the Collaboration administrator function privilege.
Procedure
The e-mail notifications will be sent to the users at the time and on the day you specified.