Navigation database updates are made available every 28 days. Updates are posted on the www.flygarmin.com website seven days before their effective date. Updates for Obstacle, Safe Taxi, and Airport Directory are available every 56 days; updates are posted on this website seven days before their effective date. Terrain databases are updated on an "as needed" basis, and not on a regular schedule. The FliteCharts database is available for update every 28-days; updates are posted on this website two days before their effective date.