Time Setting in Reports with a Show Time By List 
If your report has a Show time by drop-down list, you can specify the time frame as specific dates, relative dates, or as a period comparison.
Features
You can set the following types of time frames in reports that have a Show time by drop-down list:
You can set a time frame using specific start and end dates.
You can set a date range and periodicity using relative dates.
The periodicity can be the same frequency or more frequent than the date range. For example, if you select the Latest Week date range, you can select a time period of daily or weekly, but you cannot select a monthly time period. Any saved report using relative dates always displays the selected date range and the latest date for which there is data.
You can set a time frame that compares two time periods. Optionally, you can include a percent change column in the report, which shows the differences between the two time periods as a percentage.
You can choose to always use the latest date for which there is data, or you can select a static end date for the report.
You must refresh the view with the new time frame settings.
Activities
To set a time frame, select an item from the Show time by drop-down list, specify the appropriate settings, and click Update View to refresh the view.
To set a time frame using specific dates, select Specific Dates from the Show time by drop-down list. Then select the start date, end date, and the periodicity.
To set a date range and periodicity using relative dates, select Relative Dates. Then select the date range to analyze from the Date Range drop-down list and the periodicity from the Time Period drop-down list.
To set a time frame that compares two time periods, select Period Comparison. Then select the two periods you want to analyze from the Period drop-down list. Optionally, you can include a percent change column in the report, which shows the differences between the two time periods as a percentage by clicking Show % Change.
You can make sure you always use the latest date for which there is data by deselecting Override Latest Date. Or you can select a static end date for the report by selecting Override Latest Date and selecting an end date for the report. The Override Latest Date option is temporary for the current session. If the report was saved using Always display latest date, it has the ultimate control over whether the report is saved with an end date or the latest date.