Please, don't overwrite the original image with a "grayed" version.
A separate gray version is available.
English: Based on Timezones2008.png
|Date||(original upload date)|
|Source||Transferred fromto Commons by .|
|Author||MrMingsz at English Wikipedia|
|This work has been released into the
public domain by its author,
English Wikipedia. This applies worldwide.|
In some countries this may not be legally possible; if so: