What are the chess time limits used by FIDE? I was wondering, what time limits does FIDE use for its professional matches?
Interestingly there are two FIDE documents specifying these. Fortunately they don't contradict each other.
First, FIDE Handbook - General Rules and Technical Recommendations for Tournaments / 07. Time Control / says:

There is a single time control for all major FIDE events: 90 minutes for the first 40 moves followed by 30 minutes for the rest of the game with an addition of 30 seconds per move starting from move one.


The list of FIDE events where this single time control will be used:
Chess Olympiads
World Team Championships
Continental Team Championships
World Cup
Continental Championships
Zonal Tournaments
World Youth &amp; Junior Championships
Continental Youth &amp; Junior Championships
World School Championships
Continental Club Championships

There are some obvious omissions here. What about the World Championships? The Women's World Championships? The Candidates? What about rapid and blitz championships?
Well, section 12 of FIDE Handbook C. General Rules and Technical Recommendations for Tournaments
02. Standards of Chess Equipment, venue for FIDE Tournaments, rate of play and tie-break regulations Approved by the 2018 FIDE General Assembly
taking effect from 1 July 2019 has a full list.

The following time controls are approved for FIDE World Events:
No EVENT TIME CONTROL
1 World Championship Match 100’/40+50’/20+15’/end with incr. 30”/move, starting from move 1
2 Candidates Tournament 100’/40+50’/20+15’/end with incr. 30”/move, starting from move 1
3 World Cup 90’/40+30’/end with incr. 30”/move, starting from move 1
4 Grand Prix 100’/40+50’/20+15’/end with incr. 30”/move, starting from move 1
5 Women’s World Championship Match 90’/40+30’/end with incr. 30”/move, starting from move 1
6 Chess Olympiad 90’/40+30’/end with incr. 30”/move, starting from move 1
7 World Team Championship 90’/40+30’/end with incr. 30”/move, starting from move 1
8 Women’s World Team Championship 90’/40+30’/end with incr. 30”/move, starting from move 1
9 Women’s Grand Prix 90’/40+30’/end with incr. 30”/move, starting from move 1
10 World Senior Championship 90’/40+30’/end with incr. 30”/move, starting from move 1
11 World Senior Team Championship 90’/40+30’/end with incr. 30”/move, starting from move 1
12 World Juniors and Girls U-20 Championship 90’/40+30’/end with incr. 30”/move, starting from move 1
13 Continental Individual Championships 90’/40+30’/end with incr. 30”/move, starting from move 1
14 Continental Team Championships 90’/40+30’/end with incr. 30”/move, starting from move 1
15 World Youth 14-16-18 Championships 90’/40+30’/end with incr. 30”/move, starting from move 1
16 World Cadets 08-10-12 Championships 90’/40+30’/end with incr. 30”/move, starting from move 1
17 World Schools Individual Championships 90’/40+30’/end with incr. 30”/move, starting from move 1
18 World Schools Team Championships 90’/40+30’/end with incr. 30”/move, starting from move 1
19 World Amateur Championship 90’/40+30’/end with incr. 30”/move, starting from move 1
20 World Olympiad U-16 90’/40+30’/end with incr. 30”/move, starting from move 1
21 World Rapid Championships 15’ with incr. 10” per move, starting from move 1
22 World Blitz Championships 3’ with incr. 2” per move, starting from move 1

Just to decipher what that means. Take -

1 World Championship Match 100’/40+50’/20+15’/end with incr. 30”/move, starting from move 1

This means that
There is a 30 second increment starting from move 1
The first 40 moves have to be played in 100 minutes
The next 20 moves have to be played in an additional 50 minutes
After this (so 60 moves already played) the players get an additional 15 minutes to complete the game