Weekly resampling - Starts on mondays
After checking data from Charlie in Aurogreen, and resampling them weekly, it comes out that for example in august 2019, there is a week tagged as "18 August" in the graph, with a total rainfall of 114.8 mm, and a following week tagged as "25 AUgust" with a total rainfall of 47.6 mm. Cross checking all data from Charlie, specifically for those two weeks, the total rainfall from 12 august to 18 august matches the resampled total for the week (114.8 mm), as well as the total rainfall from 19 august to 25 august matches the resampled total for the week (47.6 mm).
Both 12 and 19 of august were mondays.
Thus the weekly resampling starts on mondays and ends on sundays.