Data updateSearch Volume data remains valid for one month before it gets updated by the Search volume sources. Yandex.Wordstat displays the data for 30 days before it expires.
The last update date is displayed on the keyword research results page.
The approximate data expiration period of other tools is one month. The tool marks expired data as 'out-of-date' or invalid. If you run a Search Volume recheck, the tool updates the expired data and charges you because the old data gets updated and replaced with a fresh data.
For your convenience this date is displayed in the Search volume tool pop-up window to the right of the source. Hover over to view the date.
To exclude unnecessary expenses and do not recheck 'old' data, uncheck a box near Update expired data. This box is available if you check a box near Skip checked Search Volume.