Answer:
12 days 16 hours 22 minutes 7.5 seconds
Explanation:
You are interested in the proportion ...
earth time / heaven time = (1000 years)/(1 day) = (x days)/(3 seconds)
Multiplying by 3 seconds, we find ...
x days = (3 seconds)(1000 years)/(1 day)
If we convert 1000 years to days, then the formula will give us "x days" as a number of seconds.
1000 years is a long enough time period that all of the leap-year rules come into play. So, we will use the average number of days in a year as 365.2425. Then 1000 years is 365,242.5 days, and we get ...
x days = (3 seconds)(354,242.5) = 1,095,727.5 seconds
There are 3600 seconds in 1 hour, so this is ...
x days = (1095727.5 s)/(3600 s/h) = 304.36875 h
The fraction of an hour converts to 22 minutes 7.5 seconds. The 304 hours converts to 12 days 16 hours.
When Gabe starts blowing his horn, we have 12 days 16 hours 22 minutes 7.5 seconds left on Earth.
_____
The number of minutes and seconds will vary, depending on what you consider to be the number of days in a year.