Sparing time with kids.
Nothing in the world gives more entertainment than this.
If they are adult then:
Sparing time on Quora and understand the people, their problems, solutions, habits, standard of living etc.
Swimming. A hour swimming increases your diet and hence sleep.
Observing ups and downs of share markets .
Study functioning of mutual funds.
Effective use of OlX.
Enjoying bold albums and memories.