Difference between on time and in time

It sound really simple but yet its a little confusing while we use this to words  

IN TIME  & NO TIME

This is the most common error, we usually make and get confused with while using it.

ON TIME

Means Exactly at the
planned

time neither late nor early.

IN TIME

It means a little early/before

schedule time.

lets have a look at some examples to make it more clear.

Lets say you have class at 8 a.m

and you reached there at 7:55 

What would you say

I reached at the class just in time.

or 

I reached at the class just on time. 

In time is the correct way to say as you have reached there before time.

I finished cooking dinner in time to take a shower 

here it means before the guests arrived or to do some other work

These are often used interchangeably,

 but they are not same

The Officer said my flight was on time

(Here my flight will take off at fixed time)

The ambulance arrived just in time at the spot

(Here it means before it was too late)

Boss want to start the meeting on time so please don’t be late.

(Here the meeting will start at fixed time)

The 1:00 pm train left on time.

(Here the train left the scheduled time)

The teacher said we had to submit our assignments by 5:00 PM

 I e-mailed her my assignment at 4:58 just in time

We often say “just in time” to emphasize that something happened immediately before the limit/deadline

Looking at the examples i hope you understand the difference between ON TIME and IN TIME

 so now you can use it in your own sentences without any confusion.