Mystical date for Peter the Great and his relatives

Today in Peter & Paul cathedral (burial place of Romanov family) in Peter & Paul fortress service after Peter the Great took place. This day seems mystical for Romanov family. Peter the Great, several years earlier his half-brother, several years earlier their father died on this very day!
The 8th of February (the 29th of January according to Julian calendar) is the day of death of Peter the Great.
He died in 1725, on the 8th of February.It is somehow mystical but in the year 1696, on this very day, on the 8th of February Peter’s half-brother and our tsar Ivan the 5th died.
(Peter and Ivan had the same father and different mothers, Ivan was older. They were on throne of Russia together from 1682 to 1696.)
One more mystical thing, father of Peter the Great and Ivan, our tsar from 1656 to 1670, Aleksey Mikhailovich also died on this very day, on the 8th of February in the year 1676.