deferral of a Ph.D. position in Europe I had an interview at a European university. After half an hour in the interview, they told me, we are positive to give you this position. The position starts in February however, the earliest time I can be there is in March. 

I would like to ask, is it possible to defer a Ph.D. position for a month or two in Europe?

In the description of this position, the start, and the end of the position along with monthly salary is clearly stated and the fund comes from a national energy utility.
Whether it is possible or not can depend on all sorts of things. The only people that can answer that truly are the people that offered you the position. You should ask them.

This is not an unreasonable thing to ask, and I can't imagine starting a month or so later would be much of a problem for a PhD (but again the only people that can tell you that are...). Negotiation of the starting date is a normal part of the hiring process.