Certainly, leopards do not need any night heating. However my little one will not come out during day to warm up, even if its past his 'up hour' with light on, only after his UV goes off. He only rarely, as in rarely rarely, will come out during day to bask. But they should not have night heating at all.

Heatmats are outdated.

 

If you’re worried, I definitely recommend get a heat mat. My leopard gecko has a heat mat; they are better for them because they absorb the heat through their bellies naturally which essential to help them digest. Switch to a heat mat if you’re worried about digesting, chances are that the heat bulb is not warming up the bottom of his vivarium enough. As for leaving heat on at night (for a heat mat), nothing bad can happen from leaving it on, I honestly don’t think it will disrupt the day/night cycle for him. Only leaving on lights will, that’s why again a heat mat is a better choice, because it obviously doesn’t emit any light. But if you’re still worried about temperature disrupting your gecko, you could easily turn down the the thermostat at night, so it’s still warm but not as warm as in the daytime. Go for under floor heating

 

No, no, no.

Firstly, matsbshould only have a very thin layer of substrate over them to avoid thermal blocking, which in turn, causes fires. They don't warm the air, and you are forcing the gecko to either be cold, or lay on hot piece of plastic. And these should not be kept with constant heat 24hours a day. It is not natural. They need a day/night cycle.
You might want to rethink your own husbandry before giving outdated and dangerous advice to others.

 

Also, I forgot to mention that any red/blue coloured bulbs may or may not cause eye/sight issues in leopards. They surely don't see the colour, but they still can see it's a light so they may think it's day time. These bulbs are really terrible!

 

Leopard geckos should have a clear day/night cycle, thus requiring a period of darkness at night. They have eyes like cats do which helps them see clearly at night time, so need no light at all.

Also, where they live there is a drop in temperatures so not even a need for night time heating as long as your house does not drop below 18°C or 16°C was it.

 

You mustn't keep any lights on at night, they need it dark at night. And it's not true that they need night heat to digest their food, they do that during the day.