Bus to Chengdu

We're traveling to lijiang by end if December. The plan is to transfer to chengdu after 4 days stay at lijiang area.

I was planning to take train to kunming, and another train from kunming to chengdu. I saw that there is a 12hour bus ride from lijiang to chengdu directly, which ends up at Xinnanmen bus station. Any info on what time and from where the bus start from Lijiang.