After moving here, you have 90 days to switch over your licence. You can drive with an existing, valid licence in the meantime.
这是原话,实际上你唯一可以证明的时间只有你第一次登陆(短登)的时间。所以,我理解90天的时间就是从你短登开始算。
Please note than when you qualify for your new B.C. licence, you’ll need to surrender your previous licence to ICBC. B.C. law requires that you only have one driver's licence.
从2013年1月开始,如果你要用原来的国内驾照直接去考5级的话,考取5级驾照以后,你的国内驾照会被收掉。建议今后国内的同胞过来要考虑清楚怎么办好。