It depends completely on the type of propulsion used to get to Mars.
Mars already has an atmosphere. It is not known how long creating an Earthlike atmosphere because we do not have the ability to terraform planets and we do not know all of the challenges it might hold.
Using current technology: it can take as little as 6 months and as long as a year to get to mars at optimum position
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You can't.
200
About 2 years. Scientists say it may take 1 year to get to Mars
it would take at least 197.456 hours to get to mars from earth
About 10 months.
1 year
8.5 months
It would take nine months.
a year on mars is equivalent to 687 earth days.