Time-based Workflow Rule Criteria

Question

When a time based workflow action is created;

1. Does it re-asses itself against the current workflow rule or the rule criteria that it originally was triggered under before it physically triggers itself?

2. If I update an oppty via an approval action that removes the oppty from the current wf rule criteria do I have to make sure that change "re-evaluate's the workflow rules after field change" in order for the timed action to drop out of the queue?

3. If I do not do "2." I assume if "1." is also not true that the timed action will still take place (which is what I am currently experiencing at the moment).

Answer 1

You asked

Does it re-assess itself against the current workflow rule or the rule criteria that it originally was triggered under before it physically triggers itself?

If the entry criteria for the original workflow rule are no longer true, SFDC automatically removes the time-based event. Otherwise, when the time trigger occurs, the actions are executed

If I update an oppty via an approval action that removes the oppty from the current wf rule criteria do I have to make sure that change "re-evaluate's the workflow rules after field change" in order for the timed action to drop out of the queue?

No, for the reasons given above, if the entry conditions for the time-based event are no longer true due to the field update, SFDC will remove the event

From the SFDC Help FAQ doc

Will the pending actions in the queue ALWAYS trigger? No. Time-dependent actions remain in the Workflow Queue until processed or the rule criteria for the Workflow Rule are evaluated as "false." If a record no longer matches the rule criteria when the rule is evaluated, Salesforce removes the time-dependent actions queued for that record.

Answer 2

If you add more or remove time triggered actions you have somehow to trigger WF rule to reevaluate the criteria, otherwise your new actions won't be scheduled (I assume this is what you are asking in 1). And to answer your second question - yes, you have to check "re-evaluate's the workflow rules after field change" to trigger WF criteria reevaluation in your approval field update.