No, you're fine. No time limits, Arc hasn't suggested that there will be any time limits.
But what could happen is that if you progress the "main story" too far without checking the "side content" you would miss out on said "side content".
But no time limits, take it at your own pace.
Even some easter eggs like the halloween event aren't based on your computer's date or some ingame date. You just have to put some halloween decoration for that to happen.