Have you ever come across a situation where you think some of your lovely day pictures might look much better at night? Try this. In 9 easy steps in Adobe Photoshop learn how to change day into night.
Tutorial after the jump.

Step 1: Open up your image in photoshop.

Step 2: Make a new layer by hitting CRTL+J.

Step 3: Go Image->Adjustments->Shadow/Highlights. Play around with the settings.

Step 4: Hit CRTL+M to bring up the Curves screen.

Step 5: You can see that the green railing is a bit too, well green. Hit CRTL+U to open the Hue/Saturation box. Get green from the drop down list and lower the saturation and lightness.

Step 6: Do the same with the blue.

Step 7: Select the bottom layer and desaturate the blue in just the same way. Now the cool part. Select the History Brush (Y). Give it a low Opacity and 'paint' the lights. This is kind of like an eraser, only it erases just the things we have done.

Step 8: One last thing we need to do is go back to the bottom layer and change the foreground color to a yellowish hew.

Step 9: Now just take the brush tool and with a low Opacity, color in the lights.