Hezu

Currently the ticket fares in Helsinki region public transport are related to the city borders of the capital region. From April 27th 2019 this will be history and the region will be divided into four zones that no longer follow the city limits.

The most people on this forum are probably interested how this affects the trips between Helsinki Airport in Vantaa and Helsinki city centre. Not significantly I would say: the centre of Helsinki will be the zone A, while HEL will be in zone C and thus the ticket type needed for this trip will be one covering zones ABC. And in case once you are in Helsinki city centre and want to use public transport then the cheapest ticket will always cover two zones and thus the choice should be a ticket for zones AB. Likewise, for the case you want only move around closer to the airport, you should pick a ticket for zones BC. The single ticket prices will be slightly more expensive than earlier, but on the other hand the area of the minimum of two zones is much larger than the earlier one city tickets and also the single tickets will be valid for slightly longer time than earlier (and allow unlimited changes within that time).
For further information, see HSL website.

:D!

So what will be the prices of day tickets? There doesn't seem to be any info on the website, which only says that prices "will" be decided in autumn 2018.

Hezu

Ah, apparently the English (or Swedish!) pages do not include the price table yet. Finnish version however exists and a quick look on the section "Vuorokausiliput" reveals that if I remember right the day ticket prices will be the same as earlier with the obvious adjustments in zones replacing the current city and regional fare types. In case you want to check the table by yourself, here is quick vocabulary: "vrk"=day (or 24h), "Aikuinen" = adult, "Lapsi"=child.