How To Make World Time Move Slower

Hey modders I'm wondering if there us any way to make the time in a world move slower? It's slightly annoying having to run to bed every 10 minutes or so and I'd like longer day cycles. I've searched for a similar question here and found none.

I've tried: On World update Tick to have a custom variable count to 40 and when hitting 40 it would reset to 0 and set World Time to:(Get World Time -20)

so that every 2 seconds the world time would move back 1 second, but this doesn't work. (I'm viewing world time as a return text from an item right click)

So I'm wondering does this not work because I am in a custom dimension?(it has day and night cycle like overworld) or is it that the set world time block doesnt work with dimensions? 

Seems like a simple thing but I am stuck, any help is greatly appreciated thanks guys.