Faking the date seemed to be the aim here, so I instantly thought of using the `faketime` command on Linux to run the exectuable.
The date to set was easy, as given in the hint "Perseverance Arrives at Mars!"
Running `faketime '2021-02-18' ./time` gives the output:
`Flag: DO{V3ry_n1Ce_t1MInG5_!1}`