Of course this isn't a problem if you wat to connect only with people in this city. But if you want to market to people over a much wider geographical area you'll have to change your strategy somewhat. Remember that when it's 9PM here, it's midnight in Sydney and Melbourne. So your Australia-focused tweets and shares could easily fall into a black hole.
Similarly, much of the content that you share early in the day will be missed by your followers in North America and Europe. That's why if you have many connections there, it's best to be active on social media late in the evening.
I've noticed the effect this can have by looking at my Twitter analytics for one of my accounts. Many of my followers are in the northern hemisphere. Engagement goes way up if I share stuff after midnight here.
Of course you don't physically have to stay up and do this all manually. You can use tools such as Buffer to spread those social media updates out.