I am a strong advocate of rest and relaxation as part of a structured and balanced fitness programme.
For myself, I try to take time out to recuperate whenever possible, preferably in the sun (!), as above, not only to rest the body but also to relax the mind. The danger in not doing this, if such options are available (and they are not regularly for many people, which is important to remember), is that training can become a grind and a battle.
Resting the body and mind allows both to come back stronger and with fresh energy, which can then be invested in a productive training lifestyle.
So, if the option is available to enjoy the sunshine or whatever it is that relaxes you, take it and embrace it with open arms!