Daylight Saving Time (DST) typically lasts for about 8 months each year in regions that observe it. In the United States, for example, DST begins on the second Sunday in March and ends on the first Sunday in November. During this period, clocks are set forward one hour, effectively shifting an hour of daylight from the morning to the evening.
The specific dates and duration can vary by country, so it's always good to check local regulations if you're unsure.