climb mount Fuji in mid march

i plan on climbing mount fuji in mid march or late march of 2021 depending on the conditions any advice to give i have climb higher peaks before and have had experience with ice climbs but still a little un easy about it and should i climb mid or late march ?

Mt. Fuji climbing season is between July and September (you can look up the exact dates). There is a reason for this - it is extremely dangerous to climb the mountain outside of these times, no matter how experienced you are. People have died trying to do so.

As a guy who reach a summit in may and saw how many people climb Fuji in off season I can say following:
1) Climbing in off season is not prohibited, just not recommended, please, check http://www.fujisan-climb.jp/en/risk/guidelines.html
2) Fuji is not hard mountain in off season if you have experience of climbing of 4000 m mountains (ideally you will need to have experience of mountaineering on glaciers, since there will be very hard crust) and have appropriate equipment. At least warm clothes, crampons, helmet, flashlight. Also since there will be big altitude difference, you need to know how do you carry altitude sickness.
3) March is worse time to climb Fuji because weather become warmer and risk of avalanches increasing drastically plus there is very strong wind. You can see at https://www.yamareco.com/modules/yamainfo/ptinfo.php?ptid=63 statistic of off season climbing. Best time for off season climbing is may and november.