Mumbai airport is to shut between 12:00 and 18:00 every Tuesday until the 8th March 2010. This closure has been put in place in order to allow essential work to be carried out on the intersection between the main and the alternative runway.
Internationally the only airlines to be affected are Jet Airways and Kingfisher Airlines as they are the only ones that operate between these times. Both Airlines have made alterations or cancellations to their schedules accordingly.
Officials have also added that as they are able to keep part of the runway open for use by smaller aircraft such as ATRs, Boeing 737's, Airbus-319 and Airbus-320 they will be able to take off and land. This should mean that short haul internal flights will remain largely unaffected.
It is very important that you check with your travel agent that any flight that you have booked is not effected by this disruption as you my find that flights have been diverted to an other airport such as Pune or Ahmedabad.