This is known as an ASO or Adjusted Schedule Opportunity. The greater the adjustment, the greater the resourcing issues that day. The idea is to move what is known as the ‘precision time schedule’ (that all working parties involved work to) forward by the allotted minutes. Your gate closing time will be respected because the flight crew and cabin crew WON’T be checking in any earlier than their original rostered time and we go when we are ready, it’s just nice to carry all your bags and have the tug turn up on time, so don’t be overly concerned.