Question

Convert this $12$ hour time into $24$ hour time. $9:20PM$

Answer 1

Hint: Here, we will convert the $12$ hour clock into a $24$ hour clock by adding $12$ hours, subtracting $12$ hours, and omitting the letters AM or PM. A $12$ hour clock starts at $12:00AM$ and ends at $11:59PM$ . A $24$ hour clock starts at $00:00$ and ends at $23:59$ .

Complete step by step answer:
A $12$ hour clock starts at $12:00AM$ and ends at $11:59PM$ . A $24$ hour clock starts at $00:00$ and ends at $23:59$ . We can convert the $12$ hour clock into a $24$ hour clock by adding $12$ hours, subtracting $12$ hours, and omitting the letters AM or PM. In some cases, we do not even need to add or subtract $12$ hours. Just omitting AM or PM converts them into a $24$ hour clock.
We subtract $12$ hours from the $12$ hour clock from $12:00AM$ to $12:59AM$ and omit AM to convert them into a $24$ hour clock. By omitting the letters AM, we can convert the $12$ hour clock into a $24$ hour clock from $01:00AM$ to $11:59AM$ . By omitting the letters PM, we can convert the $12$ hour clock into a $24$ hour clock from $12:00PM$ to $12:59PM$. We add $12$ hours to the $12$ hour clock from $1:00PM$ to $11:59PM$ and omit PM to convert them into a $24$ hour clock.
Now, the given time is $9:20PM$ . This lies in the range $1:00PM$ to $11:59PM$ . We can convert $9:20PM$into a $12$ hour clock by adding $12$ hours and omitting the letters PM.
Thus, we get $9:20+12:00=21:20$ .

Note: The $12$ to $24$ hour clock conversion is pretty easy but we should take special care of some points. We should first observe carefully that the given time lies in which range and then take the necessary action accordingly. We must remember to omit the letters AM or PM during the conversion.