Hi there.
So, for context, we have about 5 people in our house. in the fall of last year, it was said in the group chat that you don't have to pay utilities if you're gone for more than a week as that's how they had done it in the past. To help out our roommate who was in charge of the bills and struggles with math, she and I figured out the split for that month and a few months after for when people were gone.
I've been trusting her math since she took over the utilities fully when our other roommate moved out, but when I went to check the payment this month, I saw that she didn't have to pay for five days, which I found weird, as to my knowledge, she hadn't left for a week.
I asked her and she confirmed that they were the weekends that she was gone (left Friday Afternoon and came back Sunday evening).
Of course I brought up the week thing and even shared texts where the other tenants had brought it up.
She argued that she shouldn't have to pay for utilities for days that she isn't here and I argued back that she used the utilities on Friday and sunday, so even by her logic, it would only be saturday that she's not paying for.
I'm unsure if this is a reasonable split, as we had done consecutive weeks in the past.
I need help figuring this out or how to frame this without starting even further arguments.
How do you split utilities with roommates?