Originally Posted by
Some person
The currency changes from markka to riksdaler, ...
I guess you haven't landed in HEL since 2002.
But you have been there sometime after 1840, when the usage of "Riksdaler" ended in FIN. Usage of Riksdaler in STO ended in 1872 so we can pinpoint your last trip between the eastern and western capital to sometime between 1840 and 1872. No Sjöskog airport back then, but maybe on a sail ship from Skatudden to Djurgården?