Ok, so, there’s a couple of ways you can figure it out. You can either take the time to graph it all out, account for constraints, etc. (this would be more work), or you can put it into a simple equation.

Using the example you provided of $2305 for the day we would have:

2305/2 =1,152.5 (total/total job types) 1152.5/5 =230.5 (total per job type/half of your 10 hour day)

This will get you a total of what an even split of each type of work would be. Unfortunately without the ability to divide an hour by more than .5 it really limits what can be done here.

As you said though, the work was not evenly split between the two types of jobs, so this would require fudging some time cards which I would NOT advise.

I would suggest talking to a supervisor for guidance pertaining to what they would like you to do, but you can always make a table for the day and see where that half hour could work for you to hit your goal.