How Do I Make the Days Go by Faster on "Pokemon HeartGold"?by Seth Amery ; Updated September 22, 2017
Introduced as a new mechanic to the series in "Pokemon Gold," time plays a major part in various aspects of the game: evolution, store stocking hours and which wild Pokemon you'll find in an area depend on the hour or day, for example. In the remake, "Pokemon HeartGold," time still plays just as big of a role and is potentially an inconvenience to those who can only play during certain hours. The only way to speed up time in the game is to change the system date on your Nintendo DS, 2DS or 3DS console.
Nintendo DS Time/Date Settings
Remove "Pokemon HeartGold" from your Nintendo DS. It isn't strictly necessary, but this bypasses having to return to the menu if your console automatically boots games when you turn it on.
Tap the Settings icon, identifiable by the picture of a wrench. This brings you to the System Settings menu.
Open the time and date settings, which uses a clock and calendar with a blue background for an icon.
Tap the clock icon to change the current time, or the calendar icon to change the current date. Using the arrows next to each time/date entry, you can adjust the time on your Nintendo DS. Tap "Confirm" to save your changes and shut down the console.
Replace "Pokemon HeartGold" into the Nintendo DS and load your save. The game will now load and reflect the current time to whatever you set in the settings.
Setting Nintendo 2DS and 3DS Time and Date
Remove any games from your Nintendo 2DS or 3DS. Boot the device to the main menu and tap the wrench icon to open the System Settings menu.
Tap "Other Settings" on the screen, followed by "Date & Time." Depending on whether you want to manipulate the time or date, select either "Current Time" or "Today's Date," respectively.
Tap the arrows to modify the hour and minute or month, day and year. When you're done, tap "OK" to save the settings and return to the main menu.
This doesn't affect breeding and hatching eggs as these rely on steps taken, not time passed. Manipulating time only helps time-specific events, such as certain forms of evolution.
"Pokemon SoulSilver" players can also use this strategy.
Remember to turn back the clock to the right place when you're done; otherwise, you might have in-game discrepancies, such as a daytime Pokemon failing to evolve because the time is set to midnight.