The 24 Hours Clock
For Airlines, Train/Railways, and for some other specific area of workplace 24 hour time pattern is used, people work there day & night for 24 hours.
Time in the 24 hours clock is written in 4 digits
The first two digits on the left of 24 hours time pattern indicates for the hours and last two digits on the right of 24 hours time pattern indicates minutes. There is no point or dot separating the four digits.
No a.m/A.M or p.m/P.M is mentioned in 24 hours time format. Only hours mentioned.
12 o’clock noon is expressed as 1200 hours
12 o’clock midnight is expressed as 0000 hours