PostgreSQL countdown to a specified date, displayed in weeks, days, hours, minutes and seconds

gistfile1.txt

with seconds as (
select extract(epoch from ('2016-09-16 10:15:00'::timestamp - now()::timestamp)) as value
), minutes as (
select value/60 as value from seconds
), hours as (
select value/60 as value from minutes
), days as (
select value/24 as value from hours
), weeks as (
select value/7 as value from days
)

select floor(weeks.value) as weeks, floor(days.value-floor(weeks.value)*7) as days, floor(hours.value-floor(days.value)*24) as hours, floor(minutes.value-floor(hours.value)*60) as minutes, floor(seconds.value-floor(minutes.value)*60) as seconds from weeks, days, hours, minutes, seconds;