zuìhǎo xiě jùtǐ rìqī hé shíqū bǐrú běijīng shíjiān wǔ yuè shísān rì xiàwǔ sāndiǎn qián

最好写具体日期和时区，比如“北京时间 5 月 13 日下午 3 点前”。

It's best to write the specific date and time zone, such as "before 3 PM Beijing time on May 13th".