Meditation is a time-honored and hallowed practice dating back to the dawn of recorded history and certainly before that, it's just that nobody knew how to write their experiences down. These days there are skilled practitioners all over the place, advocating their particular brand and calling it mindfulness or concentration or inward focus, etc.
I can only give you what I learned as a child and have practiced on and off for decades. The holy man Sai Baba recommends meditating between the hours of 3 and 6 AM. As published on the website sathyasai.org, regularity is most important. Swami recommends a few minutes of meditation in the evening after dusk. He tells students that you have to look at any object --flame, idol, or picture for 12 seconds with total concentration and without blinking the eyelids. This is concentration (dharana). Twelve dharana concentrations make one meditation (dhyana). This means that meditation should last for 12x12 = 144 seconds. Thus, proper meditation need not last more than 2 minutes 24 secs.
Of course, this can be extended. Twelve meditations equal one samadhi, which amounts to 12x144 seconds = 28 minutes 48 seconds.
But take note, do not limit meditation to a specific time of day. Contemplation of the Lord should occur always at all places. Sri Ramana Maharshi was once asked, "How long should one practice meditation? 15 or 30 or 45 minutes or an hour?' His reply was, 'You should continue doing it till you forget that you are meditating. As long as you are conscious (physically aware) that you are meditating, it is no meditation at all."
The consciousness of body and mind and the thought of yourself should become totally extinct. The experience of only the object of your meditation should subsist, i.e. nothing else but the presence of divinity. The state of meditation is experiencing but without the consciousness that you are experiencing.
This is bliss. Get your fix today.