4383 after 8 years (including leap week)
547 x 7
554

547.875 days per years
14222 hours per year
every year they lose 22.75 hours

every 4 years  91 hours is lost - 3.5 days
every 8 years 182 hours lost - 7 days *****

it has happened 24 times and will happen in semester 5 for 25th time (end of december resetti timeline)

113958 - hours after eight years
70080 - hours after eight years on earth     2920 days