hope that my english is strong enough...

there 3 different explinations:

1.) maa(land,ground) is in maalis, in March you may see the ground in some parts of

     Finland already

    (sorry, cant believe that!)

2.) maali(target) is in maalis, it is said that in March the snow is good for skiing and

     people trained archery then

     (sorry, cant believe neither that!)

3.) maalis is formed from mahta,this is the fluency in trees, which started to flow in

     spring (my favourite explaination)

I dont know the answer to this question, but I must remind you that I'm not any professional finish teacher :D