Key takeaways from Team of Teams by General Stanley McChrystal
Measuring how hard your team is working by counting the number of hours they work or what time they get in and leave is how amateurs run companies. The number of hours worked is not the same as how effective they (and you) are.
Long hours don’t necessarily mean success. There are times when all-nighters are necessary (early days of a startup, on a project deadline) but good management is knowing when it is needed and when it is just theater.