Idle time variance

Sir I was watching your lecture on advance idle time variance which is different from the basic idle time variance in labour hours.

Idle time in basic labour variance is calculated like this:
(Actual hours rate – Actual hours worked) x Standard rate

Advance idle time variance is calculated like this:
Actual Idle time = (Actual hours paid – Actual hours worked)
Standard Idle time = (Actual hours paid x Std idle time rate)

The difference between actual idle time and standard idle time would be idle time hours which is multiplied with standard rate:
(Idle hours time x Std rate)

This advance labour idle time could only be asked with advance variances?

Is that true sir?