Embarrassing but educational mistake from my first year. Was calculating average daily usage for a client served by Oncor in Texas. Used 365 days for 2024 but forgot it was a leap year. My daily averages were off by about 0.27% which doesn't sound like much but when you're dealing with a $2M annual electric bill, that small error threw off my whole analysis. Client questioned my math and I had to redo everything. Now I always double-check whether the year I'm analyzing includes February 29th. Small details matter in this business.
Rookie mistake: Didn't account for leap year in my calculations
Howard we've all been there! I made a similar mistake early on with a MLGW account. Was calculating degree day correlations and my weather data was off because I hadn't accounted for leap year. The regression analysis looked terrible until I figured out the date mismatch. Good reminder that attention to detail separates the pros from the amateurs in this field.
I keep a simple spreadsheet now that automatically flags leap years for any date range I'm analyzing. PG&E bills can span multiple years sometimes and it's easy to lose track. Also helps when you're comparing year-over-year data - gotta make sure you're comparing apples to apples with the day counts.