At Changi Airport, time is of the essence – both for travellers and airport employees alike. The airport handles about 7,000 flights a week, or about one every 90 seconds. Hence, precise timing is a vital ingredient in ensuring the smooth operations at Changi.

 How then does the airport keep accurate time?

Ample clocks in convenient locations around the terminals

For the convenience of passengers who needs to keep tab on time, Changi Airport installed more than 600 clocks across all three terminals – to ensure that passengers do not miss their flight.

Eagle-eyed observers will notice two types of clocks at Changi - analogue and digital clocks.

These clocks may be four-faced, two-faced or single-faced, and are conveniently located around the terminals. In fact, clocks are so important, that a renowned watch brand has decided to sponsor a good number of clocks at the airport. 

Example of a two-faced analogue clock at Changi.

A Master Clock system for each terminal

Each terminal in Changi has its own Master Clock system. According to Goh Han Seng, Changi Airport Group’s Manager, Engineering, a Master Clock system transmits time displayed on to the ‘slave’ clocks that it is linked to, via electrical pulses.

As a result, all the clocks in the terminal will reflect a single timing, so that all passengers will refer to the same time even though they are at different locations in a terminal.

“With this Master Clock system, the rest of the ‘slave’ clocks at Changi is fully automated and requires minimum maintenance” says Goh. 

Accurate? You bet.

How accurate do Changi Airport’s clocks get?

The Master Clock system uses satellite-based Global Positioning System (GPS) technology to ensure accuracy in the time displayed. The master clocks in Terminals 1, 2, 3 and eventually 4 when it is operational, have their times synchronised by GPS, thereby ensuring that the times displayed on our clocks throughout all the terminals are in-line with international standards, Goh explained. 

Each Master Clock system then transmits this time to the ‘slave’ clocks it is linked to. This is how Changi Airport ensures that passengers get the most accurate timing possible, across all its terminals.

Diagram depicting Master Clock system.

Ever reliable

The maintenance teams at Changi Airport conducts weekly checks on the clocks, to ensure that they continue to run smoothly. These checks typically involve checking the clocks’ time synchronization, as well as the LED lights for digital clocks, and illumination lights for analogue clocks.

Thanks to Changi’s impeccably accurate time displays, passengers won’t ever have to worry about getting the wrong time and missing their flights!