An attorney's life is ruled by the calendar! If they miss a deadline, it could be costly for their client, and could be considered grounds for malpractice. So, even though I have never been a lawyer, I have done contract work for them, and know this is VERY important. Always check the calendar, not just for that day, but the next few days.
There are many different types of lawyers, so they all do different things. A lot also depends on if they are solo practitioners or have a staff. There are emails to check and respond to, voice messages, etc. The lawyers I worked for belonged to a chat group where they helped each other with legal arguments for very complex cases. It was amazing to see the degree of collaboration between them! This was also an important part of their day.
If the lawyers are in litigation, they will need to stay in touch with opposing counsel, file motions with the court, make court appearances. They need to follow a very structured set of rules as to how to file, giving copies to other parties, etc. I still cannot believe how many rules they have for things!
I hope this has helped a little. I know there is much much more that they do!