notetested
Compare complete periods, not whatever today has finished
Two equal, completed time windows give a clearer trend than comparing a partial current period with a full previous one.
A month-to-month comparison can look dramatic simply because one month is only three days old. The chart is mathematically correct and practically misleading.
For an operational snapshot, compare the last seven complete days with the seven complete days before them. Exclude the still-changing current day, label both ranges, and keep the windows equal. Calendar months still have their place, but they are a poor default when the real question is, ‘Are things improving lately?’