By default, players are reminded of each fixture twice: once on the day after a fixture (regarding their next fixture) and once on the day before a fixture. This way players have two opportunities to inform their team captains of their availabilities, and you as the venue or league managers have two chances to communicate with the players to inform them of their fixtures and any other information you want to tell them.
In some instances, you may wish to turn on or off these reminders, or you may wish to have the reminders sent on a different schedule. This is useful if for instance you create your fixtures only one week in advance. In these cases, reminders that go out on the day after previous fixtures may be no good, as the next fixture may not yet have been created, so the reminder will be skipped.
To modify the fixture reminder schedule for a venue, follow these steps:
1) Click "Config"
2) Click "Scheduled Task Configuration"
3) Click on the reminder for which you want to modify the schedule
To change the fixture reminder schedule for a particular venue, first select the venue from the "Version" drop down list (note that if you are an administrator, a "Top Level" item will also appear in this list, and this is the item that you should modify if you wish to change the schedule for ALL venues). Then, you can change the schedule using the options in the "Schedule Details" section. Note that in most instances, it will be sufficient to inherit the fixture reminder schedule from the parent of this item.
To modify the fixture reminder schedule for a particular league, simply click the "Reminders" link from the League Details page. Changes on this page will only influence that League.