Ah, very clever NS! NS is our national train system. Last year they got slammed when it snowed and many trains had to be cancelled. Actually, it happened the year before that as well. In fact pretty much every winter there is snow (shock!) and up until this winter, every year the NS has miserably failed to keep trains running.
So this year they got smart - in anticipation of freezing temperatures and snow, they just up and cancelled half the normally scheduled trains. On the plus side - at least in my experience so far the trains they have kept running have been on time. Apparently as part of the their contract to deliver service nationally the NS is only allowed to be late for some period before they incur fines.
Still it totally feels like cheating.