I have $10.73$ and $37.27$ days and I need to convert both to the days:hours format but I'm getting confused mid way.
Taking $10.73$ as example I can do $10.73\times24$ to get $257.52$ hours but how do I go about presenting it that 10.73 days is equal to x days and y hours?
You can remove the $10$ for the number of days. This leaves you with $0.73$ days that you need to present as hours. $$0.73\cdot24=17.52$$
As days:hours, it's $10:17.52$
Alternatively you could take the number of hours ($257.52$). Divide by $24$ and round down to get the days, and mod by $24$ for hours.
$$\lfloor\frac{257.52}{24}\rfloor=10$$ $$257.52 \bmod 24 \equiv 17.52$$
It appears your time of $10.73$ is decimals of days, in which case you already know that there are $10$ days. To get the number of hours, you multiply $0.73 \times 24=17.52$ so there are $17$ full hours. To keep going you multiply $0.52 \times 60=31.2$ to get the minutes and $0.2 \times 60=12$ to get the seconds. The final answer is $10:17:31:12$