If you have never gotten any kind of goods or documents delivered within Singapore before, what you will realize is that all couriers charge surcharges for night and weekend deliveries if you have ad hoc deliveries. Perhaps only for people (consumers or businesses) who have high volume of deliveries (e.g. E-commerce companies), courier companies might offer waivers on such extra charges.
However, for the vast majority of customers, courier services in Singapore would have a small fee for such deliveries. So please do not be alarmed if you were charged that. It is simply because most couriers do not work on week nights as well as weekends, and so the courier company would have to pay them more to keep them motivated to help deliver goods on such timings (e.g. night and weekends).
How about public holidays? Are there companies which deliver goods or documents on public holidays in Singapore? I believe there is, but only an extremely small minority of couriers would be willing to do it. Hence, be prepared to pay a special premium on that day. However, in general, it is still cheaper to pay a courier for his or her services than it is to take a cab to-and-fro. This is reason why courier services are still higher popular in Singapore – because cabs and cars are not exactly cheap, while public transport can be really crowded and slow.
All in all, even with the weekend and night surcharges for deliveries in Singapore, I can say that it is still much more efficient and affordable to get a courier service to help you out. No point cabbing around or lugging along your package or document on public transport. Just get a reliable courier service and all your troubles would be solved! You would not even need to step out of your house’s doorstep. How much more efficient and convenient can it be? :))