Start a timer in seconds, try the Pomodoro technique or just looking for a (world)clock in your menu bar?
Check out these Mac Menu Bar Time Apps:
Collection:
Time Apps
Time Zone Pro
This menu bar app keeps track of lots of different time zones. Add your friends, family, clients or team and never schedule a call over dinner or bath time again.
Contacts, time zones and avatars are automatically synced across your iOS and macOS devices.
Collection:
Calendar Apps | Time Apps
The Clock 4
With this clock and timezone menu bar app you can easily keep track of your contacts in different time zones. You can also set up meetings with the Meeting Planner.