The time of day affects quite a few things in Dragon Quest 3 remakeand it is definitely advantageous to do certain things at certain times. Each city has some differences between its daytime and nighttime versions, and certain specific locations have things you can only do at certain times of the day.

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There are a few different ways to progress through time in Dragon Quest 3 Remake, though most of them won't be available at the start. Most of these different ways have different costs, be it gold, MP, or something else entirely.
Sleeping in an inn (or at home)
The first way to spend your time is how you will do it from the very beginning: he is resting. This can be done at the inn at different costs depending on where in the world the Inn is located, or can be at home in your mother's housefor free.
When you rest at the inn, you will have the option to wait a set time. If you don't just want to restore your characters to full health and MP, you can wait until you stay overnight or rest until a set time, either dawn, noon, dusk, or night.
How to use the night light
If you want to set it specifically for night and don't need to restore your characters health or MP then Night light will be an item for work. You must be on the world map use the night light, but when you do, it immediately shrouds the world in the darkness of evening.
Night light it costs nothing to usebut it's an item you'll have to find. Potential spoiler below:
Night light is obtained in the village Theddon, which is on the southwest part of the mapsouth of the mountains and the desert, directly south of Ibis. The night light is located on second floor shop on the south side of the villagein the chest.
How to use the Tick-Tock charm
There is magic which can also change the time of day, the so-called Tick-Tock. Once you have either a mage or a level 25 sageyou will have access to Tick-Tock, and that is very convenient way to flip the time of dayassuming you have 12 MP to send.
Spend some time grinding
The final way to change the time of day is the old-fashioned way: you could just wait for it. There is always an advantage grinding in Dragon Quest 3 Remakeso there's no harm in just wandering around the world map, fighting some monsters and getting some gold and XP. Before you know it, it will be the time you've been waiting for and you can get on with what you've been doing.

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