You can include a confirmation link via email allowing your volunteers to let you know that they will be attending an assigned shift. This is available when sending emails from the Calendar view. This link works without the volunteer having to log into their Dashboard.
From the Opportunities Tab, select the Opportunity that has shifts, then click on Calendar. From the Month view, right-click on the shift for which you would like to send confirmation links and select Email. 
This will bring up the Email window. For the "To:" select All Placed Volunteers in Shift or All Referred Volunteers in Shift. Continue setting up your email. To add the Confirm Link, click on Schedule Session Mail Merge Fields and type in "link" in the search box. Select the "Sch:Confirm Link", click where you would like to place in the email body, and then click on Insert. If you will be using this again, be sure to save this as a template.
This is how the email will look to the volunteer:
When they click the link, they will then see the following:
In eCoordinator, you will then see that they have confirmed their shift:
Or by creating a grid that contains the Shift Confirm field:
You are also able to set automation triggers based on volunteers confirming their shifts.
