Is it daylight saving or daylight savings?

it is Daylight Saving Time- no S after Saving

BUT

Most people say Daylight Savings Time..Why?

When people say the phrase 'Daylight Savings Time' it sounds like a possessive noun, as in, the time that belongs to Daylight Saving, hence it's Daylight Saving's time. But, in actuality "Daylight Saving" is being used as an adjective - as in time that is saving daylight.