On Ascension Day, or some other day in May, citizens of the Baselbiet region are invited by their local town council to walk along parts of the regional boundaries, accompanied by a local official or forester, flag bearers, and musicians. Some communities also organize a special church service on the occasion. In a chosen spot, the president of the town council greets the crowd, introduces new citizens, and discusses questions pertinent to the community. A meal then follows which, in many places, is paid for by the local community.

The tradition of Banntag - the community boundary day - practically disappeared in the first half of the 20th century, but was revived after World War II. The authorities realized that the Banntag was an excellent occasion for them to meet the people in their community, while, at the same time, offering local residents a chance to get to know each other and celebrate together.