QS:Time limit warning
From LimeSurvey Manual
Time limit warning message timer (time_limit_warning)
Description
With the help of this attribute, you can set the time (in seconds) when the time_limit_warning_message will be displayed before the time limit expires. Setting a value for this attribute activates the time limit warning message.
This settings is only applicable if the general time limit settings is activated. This setting also exists for a second warning message.
Example
If you set this to '20', then the time limit warning message will appear 20 seconds before the time limit countdown reaches zero.