From MozillaZine Knowledge Base
This preference determines the amount of time between application update checks.
Possible values and their effects
The number of seconds between update checks. (Default: 86400, or 1 day)
- app.update.enabled must be set to true for this preference to take effect.
In Firefox and Thunderbird 1.0.x and below, this preference was measured in milliseconds.
First checked in
Has an effect in
- Firefox (all versions since 1.0)
- Thunderbird (all versions since 1.0)