A labour unions’ demonstration / strike will stop most of traffic in Finland this week on Friday. Also Finnair flights departing from Finland will be affected for some hours. It is difficult to estimate how wide the consequences are to flights in general.
Consumers are advised to follow the information of their airlines and to keep in mind passenger rights in flight cancellations and delays.
For further information, please see for example: Finnair: Strike to affect thousands of travellers (YLE News)
Finnair's flight information