Can I continue to make HSA contribution when I was insured in Cobra plan which is also HDHP?

I was insured in HDHP medical insurance and made HSA contribution between 1/1/14 to 04/25/16. After 04/25/16 to now, I am insured in Cobra plan which is also HDHP.  Also when will be the last day to make 2016 HSA contribution?