How to send Alert email based on Assignment (Start) Date?

Summary:

We want emails sent out after the training becomes available to employees. Would that be the Assignment Date?

Content (required):

Hi Everyone,

We started to use Alerts Composer to notify employees about the training assigned. Our plan was to send an email to employees after training got assigned to them:

1) We want emails sent out after the training becomes available to employees. Would that be the Assignment Date?

Would the filter expression below work?:

${assignedDate}>=sysdate-1 AND ${assignedDate}<=sysdate

2) To clarify - we Don't want emails sent out for the assignments that are created but aren't visible yet, therefore AssignmentCreatedDate can't be used I believe