Brussels -- Switzerland is to join the European Union's free-movement Schengen area as of Dec. 12, the bloc's interior ministers agreed last week.

Systematic land border controls for people traveling between Switzerland and neighboring EU countries will be terminated on that date, allowing Swiss and EU citizens to visit one another's countries without having to show their passports.

Passengers on flights between Swiss airports and Schengen-zone destinations, however, will continue to have to show their passports until March 29 -- the date on which European airlines are set to switch from winter to summer timetables.

This is because aircraft landing in and taking off from European airports take their passengers on board from different terminals, depending on whether the flight links two Schengen cities or crosses the Schengen zone's border.

EU airports would therefore have to re-draw their entire flight schedules to accommodate Switzerland's change from non-Schengen to Schengen status, while Swiss airports would have to change their flight schedules to set up new Schengen and non-Schengen terminals.

The decision to wait until the March timetable change allows airports to incorporate the shift in Schengen states into the larger exercise of re-allocating runway space for the summer season.

The Schengen passport-free zone was originally created by France, Germany, Belgium, the Netherlands and Luxembourg in 1985 near the Luxembourg town of Schengen, and put into practice in 1990.

It was expanded to cover the larger EU in 1995, although Britain and Ireland -- the EU's two main island member states - decided not to join the system, preserving their own border systems.

Non-EU members Norway and Iceland also joined the zone in 2001, as they were already part of a passport-free zone with EU members Denmark and Sweden.

The latest expansion came at the end of 2007, with the introduction of nine new EU member states, mostly in Central and Eastern Europe: Estonia, Latvia, Malta, Lithuania, Poland, Hungary, Slovakia, the Czech Republic and Slovenia.

The decision to bring Switzerland into the zone was taken at a meeting of EU justice and interior ministers in Brussels.

DPA/Expatica