No it's not. Legally the age is either 16 or 18, but it is not enforced at all. I could literally send my 4 year old son to buy me some beer or whisky and they would sell it to him.
You don't see two year old drunk or hardly any teenager for that matter. The reason is that since you can buy any time you feel like it is not a big deal as it is in other countries. For instance, my 14-15 year old nephews go to the bars or parties and drink beer. They do so in moderation and not because they have to, but because it is just not a big deal to buy alcohol.