2 sentences

1. 让圣诞倒计时开始！

   ràng shèng​dàn dào​jì​shí kāi​shǐ!

   Let the Christmas countdown commence!

   Source: CCMatrix

2. 倒计时开始了。

   dào​jì​shí kāi​shǐ le.

   The countdown has begun.

   Source: OpenSubtitles