Case - Send Escalation Email Alert (Timeout)

Hi, looking for advice on how to best achieve this scenario:
After Case creation, a customer wants an email notification sent to the Owner alerting them that the Case is not yet Resolved:
If Priority equals HIGH - 24 Hours, send an email 1 day after Case Created On
If Priority equals NORMAL - 3 Days, send an email 3 days after Case Created On
If Priority equals LOW - 30 Days, send an email 30 days after Case Created On

If Priority equals 'On Hold' Pause the email notification

I have this set as

Scope: Organization (obvs)

Start Workflow when: Record Fields change - Created On

Timeout - 1 Day Duration, 2 Days Duration etc., but it is not working.  Can someone model the best way to achieve this scenario?