The Orthodox believe the soul of the departed stays near Earth for 40 days after death. (I'm not sure why -- to comfort those remaining? haunt those responsible? take care of unfinished business?) They have a funeral (traditionally open-casket and very emotional) -- then 40 days later they have a party, as the SOUL leaves Earth and goes home to Heaven. It is a lovely thought...
This is a good religion, comfort in time of loss. And you're right the 40 days will come in handy for in-depth planning.
40 days - the number of days Jesus walked the earth after His death and before His Ascension into Heaven.