In Amplitude, you use the datepicker to select the timeframe of the analysis you're conducting. In many ways, it's very intuitive, as it's something you've most likely seen in other software contexts. You can choose to analyze data collected between two dates, since a specific date, or in the last x days, weeks, or months, where x is a value you select.
However, there are certain nuances to the way the datepicker understands time. This FAQ will clarify these nuances for you.
Last
When using Last, your queries will return the data from the timeframe you specified, as well as the latest, still-incomplete interval.
For example, if you set the datepicker to the last seven days, you'll get data from the last seven full days, and data from however many hours have elapsed today.
The dotted line that's framing August 17 tells you that the data for that day is incomplete. (Similarly, you'd see this data represented on a chart as a dotted line.)
If you'd rather not get data from the incomplete day, you can use an offset. In this example, set the datepicker to collect data from the last six days, offset by one. If you want to query the last 7 complete days without any partial data, select Last 6 days, offset by 1.
Here, the August 17 square is no longer surrounded by a dotted line. This is because it's excluded from the analysis; instead, you'll get data for the six full days you specified, plus the full offset day, making for a grand total of seven days.
last 7D actually includes current day too so can show 8 days
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