Another nice expression is "hard times", which is pretty close to "tough time" but is often applied to society at large. For example, "during these hard times it's hard for people to afford to put food on their table".

When you're going through a tough time, things are hard and you have to work hard to get through it. If you're having a rough time of things, you're going through a tough experience. Hope this helps :)

when can we start it?

Hi Cindy, great question! I would say tough time is more when you are going through something and you keep going or you are struggling through something. I would say this is more within your control. E.g. I'm completing this problem but I'm having a tough time figuring out the answer. For rough time, this would be more difficult time that is probably more beyond your control. For example, he's out of luck, he's had a rough time.

hello can we practice together?