The discount applies from 9am to 4pm, and after 7pm. The discount is 40% on all single and return tickets.

Normally, the discount only applies to NS discount card holders. The Dutch Railways give the extra discount on the request of the Dutch government.
Due to the continued snowfall, there are less trains than normal, and with the extra discount the Dutch Railways hope to have as few passengers as possible during the rush hours.

At the moment, the traffic conditions in and around Amsterdam are not very problematic, but if you have to travel you may want to take some extra time.