The artificial strengthening of what is today a fragile ozone layer will be a long-term process on which generations will work. The ozone layer will protect tender protoplants, create a greenhouse effect and in this way raise and balance the temperature on the planet's surface. Ice from the crust of Mars will melt into water, which will flow again in the already known Martian channels. Clouds will move across the sky and perhaps release a storm. If fertile ground is prepared, seeds will germinate on their own.
Life always finds a way.
A day will come when everything is ready. Humankind will set foot on Mars with the intention of staying for some time. We will sleep on the red planet. And for those days that we spend on Mars, the terrestrial system of measuring time will no longer help. It will be even less help to those that are going to settle there for ever.