[astro] Fixed timeLeft calculation at the end of the year (#11889)

[astro] Fixed timeLeft calculation at the end of the year (#11889)

Season timeleft calculated the wrong time at the end of the year, because the seasons it measures the time with are the seasons within the same year.
So for times at the end of the year it computed against the season at the beginning of the year, resulting in negative number of days.
Also changed the time of timeLeft to actual days instead of quantity unit days.
Because with the milliseconds internal resolution it will generate events each and every time this channel is updated as milliseconds change often.

Signed-off-by: Hilbrand Bouwkamp <hilbrand@h72.nl>