The access timer begins when you click Start Lab. The lab ends when the timer runs out, or when you click End Lab if you complete it early.
Lab access time is generally twice as long as the average time it takes to finish a lab. The lab resources (your temporary credentials and access to the Cloud) are available during the lab access time.
Subscriptions, credits, and access time
Access time for a particular lab is the same, regardless of whether you paid with credits, used an event token, or have a subscription.