Help explain tier points and moving between red-silver-gold?

Hi everyone. Is anyone able to explain...I am currently red but have enough flights booked in in the next couple of months that should take me to gold. Once achieving gold..how long do I keep gold and from what date is gold from? Once what I think is 12-13 months I lose gold do I go automatically to silver (assuming no more flights are made after getting gold) If I am at silver after that 12/13 months can I achieve gold again and is this by getting 600 points only not the 1000 red-gold or would I have to get 1000 again? I hope that makes sense?!!

Thanks for your help --anyone!

You will have gold for 12/13 months from the day you attain gold. Your tier points will reset on attaining gold for the first time too. You will then have a soft landing to silver, depending on your tier points level when you drop to silver, you may well need the full 1000 to get back to gold again.