The update schedule for each database is listed on each database page. In the vast majority of cases, data updates are on a 120 day basis, which is our minimum schedule. Please note that the number of days listed for an update is the 'minimum' days.
Just because a product is listed on a 120 day schedule for example, does not mean that it is exactly 120 day's and that's it. If there are high volumes of activity additions, changes or deletions updates occur more frequently. Note that the Master Rights license is the only license that allows access to these updates at the reduced rate.
If you are having issues location the update schedule on the product page, it is always just to the left on the pricing information at the top of the page: