why I am no longer getting good quality of international call to Taiwan after daylight saving ended.

hi, I am no longer to get good quality of international call to Taiwan after daylight saving ended.   My usual time to call my parents in Taiwan, usually around 9p-10p( central time) in the States.   Before daylight saving time ended, I did not have issues.  But after that,  huge issues every time I tried to call.   It has been for at least 2 weeks now and did not get any better.   

thanks,

w.c. Jessica