Any other countries that celebrate "Coming of Age Day"? howibecametexan.com

Seijin-no-hi (Coming of Age Day) is a Japanese public holiday that occurs on every second Monday of January. This holiday honors people who have reached or will, the age of twenty within the current year.

Throughout most of Japan, twenty is the age where people are subjected to adult laws, gain the right to vote, and to drink, thus making the age of twenty is the age of adulthood in Japan.

Usually, the ceremony takes place in the morning and all the "new adults" in area are invited. They can be celebrated at local and prefectural offices and include the families and friends of the new adults. During these ceremonies, government officials tend to give speeches in honor. Small presents are also given to the new adults.

Here is a good article by a foreign resident who actually attended the ceremony.

Do other countries have similar events for those who just reached adulthood?