What is the importance of style book for newspapers?

Unlike most of the other print media, newspapers usually keep a style sheet to be followed so that there is a standard method of editing and presenting articles, an easy visual flow and because it highlights their unique professional touch.
The style sheet helps the sub editors in presenting information in a standardized manner as already decided by the editors.
It saves time by making the job of the sub eds easier by helping them decide : whether to use American/British spellings, how to write the designations of the important people, how to write the dates, the days, writing the numbers in numerical form etc.