You can meditate whenever it feels best for you to, but meditating throughout different times of the day provides different benefits.
For example, many people enjoy meditating in the morning when they wake up. Morning meditation is good to help you wake up and start your day on the right foot. During morning meditation, you can set intentions for the day.
A lot of people prefer to meditate when they get home from work too, to help relax and decompress from their day. My personal favorite time to meditate is before bed, as it aids in relaxation and helps me fall asleep easier.
