Unable to use rules to update field after the first update I currently have a field that shows the last updated date on a user edit page. 

I'm using the current configuration for rules.

Event:
    After updating an existing user account
    After saving a new user account

Conditions
    Entity has field
      Parameter: Entity: [account], Field: field_last_updated

Actions
    Set a data value
      Paremter: Data: [account:field_last_updated], Value: now


It works great the first time but subsequent updates do not update the last_updated field with the current time. Is there something I'm doing wrong?
The issue appeared to be that the 'last updated time' field was updating only in 15 minute increments. Though I'm still not sure why it is in 15 minutes increments or how to turn that off.