wow just some wild guesses here, no idea if it is right:

i'm assuming ticks means what i found on my search internet search:

declare @ticks bigint = 624511296000000000;

--One Tick is 10 ns. So one second is 10 million ticks

select @ticks = @ticks / 10000000;

--60 seconds to a minute, 60 minutes ot an hour

select @ticks = @ticks / (60 * 60);

--add those minutes to the min date of SQL server?

select DATEADD(hh,@ticks,'1900-01-01')

--3878-12-31 00:00:00.000

--maybe that date is from 0 BC?

select DATEADD(year,-1900,DATEADD(hh,@ticks,'1900-01-01'))

--1978-12-31 00:00:00.000