Less Meeting syncs with Gmail/Google Apps every 30 minutes.
To see the last time your calendar synced go to the Google Apps page from the Settings screen and note the time next to the "Un-link" button (or click here).
Note: If your account isn't linked the last sync time won't display.
If after 30 minutes you are still not seeing your meeting appear, your meeting may not meet the criteria to be synced. Click here for more information.