Differential pricing for petrol

My friend pointed out to me the price of 1 litre of petrol, as displayed in a prominent sign at the petrol stations. The price was around CAD 1.05 in the morning and reduces in stages to CAD 0.95 at around midnight. The next morning, the price went back to CAD 1.05.

The petrol station used differential pricing to encourage some drivers to fill up the tank during the night hours. This helps to reduce the crowd at the petrol station during the working hours.  It is an interesting way to spread out the queue.  

Perhaps petrol stations in Singapore can consider a similar strategy? It seems to work quite well in Canada.