How does Daylight Savings time work for ghosts?

“We do not need it”, real quote from a ghost.

Same as the rest of us. One always turns up an hour late 

I’d say that given the “Witching Hour” is more human superstition than reality, you could safely move it forward an hour along with daylight saving time. 3am on the clock is probably scarier than 4am. 

There are NO such things as ghosts. Once a person passes away, their spirit goes back to God. There is no "hanging around" [Ghosts], or "coming back in a different form" [Reincarnation]. Once you die, you will face God. Will it be before the Great White Throne or the Throne of Judgement? YOUR choice. I am going to be standing before the Throne of Judgement.

Not noticed this 3am thing myself. Most of my sightings have just been when I was there which is any time of day.

 I think it is a phenomenon largely based on heresay.

Questions like yours could incite Critical Thinking among believers but sadly, not among trolls who don't even know what critical thinking is. Bless their little cotton socks.

Questions like yours could incite Critical Thinking and will not be appreciated by many paranormal fans. More likely seen as a swipe at their intelligence than pointing in the right direction. To answer the question. There is much we don't know about Science. 

Most ghosts work from dusk to dawn so they don't watch the clock just the sun.

re anniversaries, how about from the era when countries were converting from Julian calendar to the Gregorian calendar? different countries converted at different years, so at one point there were many days difference between them. 

For example, England lost 15 days: "From Tuesday September 1, O.S. to Saturday September 16, N.S. 1752". Other countries did this in different years. Russia, for example, in 1918.