Daytime Energy Glasses are best if you spend your day in front of a screen. They are also recommended if you are in an environment with traditional lighting (LEDs, fluorescent bulbs etc) for long periods of time. They can also be used to night for those who are not privy to the idea of seeing the world through rose coloured glasses..literally 
Nighttime Sleep Glasses should be used if you are exposed to any artificial light at night. This includes phones, computers, tablets, TVs, light fixtures (overhead lights or side lamps). Nighttime Sleep Glasses are recommended 1-3 hours before bedtime for optimal melatonin release.
It's a good idea to get one of each pair if this is accessible to you! If you can only choose one at this time, Daytime Energy Glasses are a safe bet as they can be also be worn at night.