does everyone observe daylight savings
In North America, most of the US and much of Canada observe Daylight Saving Time and in Europe, most of Western Europe observes Daylight Saving Time but there are notable exceptions such as Arizona and Hawaii in the US, Saskatchewan and parts of Ontario in Canada and Iceland.
It is generally only used during the daylight saving time for places that observe Pacific Standard Time (PST) during the non-daylight saving period. As mentioned earlier, most parts of Arizona do not observe daylight saving time, so these parts remain on MST. The Navajo Nation lands, which extend to the states of Arizona, New Mexico and Utah, observe daylight saving time from April to October.