Hi and welcome, no, you should not convert it to the Beijing time zone, but use your local time.
I have done many divinations for clients and friends from many countries with very different time zones than GMT+8. If I convert the time to GMT+8 (Beijing) then I may get a day Branch that would not fit with the case in hand.
Most active members in Liu Yao boards here are actually from Europe and the US. You can see that they also use the local time without any problem.
Also, if you are in, let's say, the GMT+0 time zone and consult with a master in the GMT+8 zone (China, Hong Kong, Taiwan, Singapore, Malaysia etc.), please use YOUR local time zone of GMT+0, not the master's time zone.