@bx that was the social contact for the longest time before, but now that is inconsistent across companies and managers. I would never ever recommend anyone go beyond their job description, and especially if it required giving extra time. If you can finish your normal duties early and have extra time on the clock, them maybe it's pursuable, but the best majority of people I've seen burn themselves out to try for a promotion and then get fu---d over far exceeds the success rate.
If it's not clearly outlined in writing on how to get promoted, then never assume you'll get it.