To customize your reminder settings for all entries occurring in one of your calendars, follow these steps:

1. In the calendar list on the left, click the down-arrow button next to the appropriate calendar, then select Notifications. (Alternatively, click the Settings link at the bottom of the calendar list, then click the Notifications link to the right of the appropriate calendar).
   
   
   
   
2. In the Event reminders section, select the reminder method from the drop-down menu and enter the corresponding reminder time (between one minute and four weeks). If you'd like to add additional default reminders, simply click Add another reminder.
   
   
   
   
   
3. You can also choose to be notified of specific activities on the calendar by selecting the appropriate options in the Choose how you would like to be notified section.
4. Click Save.

Please note: when you make changes to the reminder settings for events on your calendar, the changes will only apply to you. Invited guests or those who have access to the events will receive reminders according to their own Google Calendar reminder settings.

This means your students will not automatically receive reminders even if you set the 'Homework' calendar to have a day-before email reminder. The students would need to set this reminder themselves.