P. 8 of the Vigil Manual:
"The selected activation mode «PRO», «STUDENT» or «TANDEM» will remain visible on the LCD display until the Vigil® is switched off or turns off automatically after 14 hours. If the Vigil is airborne due to a difference in pressure equivalent to more than ±150ft (±46m) compared to the “ground zero” reference (pressure), it is highly recommended to switch off your Vigil® after your last jump of the day. Be aware that your Vigil® will not switch off as long as its “ground zero” reference altitude is not measured again (at ±150ft or ± 46m) by the Vigil®."
Hope that helps a little