Google Ad Manager's query creator has a wide variety of dynamic date range options, but they are not entirely consistent. Take, for example, the surprising difference between 'Last year' and 'Last three years':
Selecting 'Last year' shows data from the previous calendar year. If I were to choose this now, on 24 October 2019, my query would show me the data from 1 January to 31 December 2018. ('Last 3 months', 'last 6 months' and 'Last quarter' - among other options - all follow the same logic.)
However, 'Last three years' shows data from the three-year period immediately preceding the current date (rather than the previous three calendar years as one might expect). If I were to choose it now, on 24 October 2019, my query would show me the data from 24 October 2016 to 23 October 2019. And this would only become apparent when I choose to view the results of the query, not during the query creation process.
Really, the wording here should be clearer - 'Previous calendar year' and 'Three years to current date' are my suggestions. Or perhaps tooltips could be put to use.
I am also rather intrigued by the dropdown on the word 'Last', which for me at least has only the one option: 'Last'. I cannot help but wonder whether other options have been removed or are yet to be added.
On a similar note, I do not understand why some of the 'Last' options, such as 'Last 3 months', have a radio button of their own - but others, such as 'Last month', appear in a drop-down list.
Finally, for the sake of clarity, here are what all the various date range options would give you were you to select them on Thursday 24 October 2019. All dates shown are inclusive.
|Today||24 Oct 2019|
|Yesterday||23 Oct 2019|
|Last 7 days||17 Oct 2019 to 23 Oct 2019|
|Last 30 days||24 Sep 2019 to 23 Oct 2019|
|Last 3 months||1 Jul 2019 to 30 Sep 2019|
|Last 6 months||1 Apr 2019 to 30 Sep 2019|
|Last 3 years||24 Oct 2016 to 23 Oct 2019||Not calendar years|
|Last week||14 Oct 2019 to 20 Oct 2019||Week starts on Mon|
|Last month||1 Sep 2019 to 30 Sep 2019|
|Last quarter||1 Jul 2019 to 30 Sep 2019|
|Last year||1 Jan 2018 to 31 Dec 2018|
|Week to date||21 Oct 2019 to 23 Oct 2019||Does not include current day|
|Month to date||1 Oct 2019 to 23 Oct 2019||Does not include current day|
|Quarter to date||1 Oct 2019 to 23 Oct 2019||Does not include current day|
|Year to date||1 Jan 2019 to 23 Oct 2019||Does not include current day|