The World Clock lets you display the time in numerous cities around the world. 

When the clock face is dark, it is night-time in that city. When the clock face is white, it is daytime.

To add a city:

Tap the + sign in the middle of the clock in the upper right hand corner of the screen, then use the virtual keyboard to start typing a city name.

You can create clocks for many cities but only six cities at a time appear onscreen.

( Note; IF you cannot see the + sign there are more than six clocks on display, scroll from the left.)

To remove a city:

Tap Edit on the top ;eft hand side of the screen and then tap the red circle that appears to the left hand of the city you want to delete. Then tap Delete.

To rearrange the order of the cities:

Tap Edit, then press your finger against the symbol with three horizontal lines to the right of the city you want to move up or down the list.Drag the city to a new place on the list.