Rushabh Lathia <rushabh(dot)lathia(at)gmail(dot)com> writes:
> I thought when we are providing the different format into to_char for
> datetime then standard datetime input converters should also have the
> capability to read that format.
to_char is designed to support a near-infinite number of output formats,
including many that are necessarily ambiguous. There is no intention
whatsoever that they all be readable by the input converters.
It might or might not be useful to adjust the input converters to read
the specific format you chose. But "to_char produced it" is simply not
an interesting argument in favor of that.
regards, tom lane