I have 5 columns: Start Date, Start Time, End Date, End Time and Duration. I need to calculate the duration between the Start Date/Start Time and the End Date/End Time. I tried just subtracting the end time from the start time, but I am having issues when it spans two days. I haven't been able to find a solution that doesn't require me to add two new columns (Start Date/Time and End Date/Time). Any ideas?

![enter image description here](https://i.stack.imgur.com/1gcw3.png)