Unless you're extremely lucky (in the sense that you exist in a very particular line of place in each time zone), it is off by an arbitrary and varying amount for everyone everywhere all the time regardless of DST or not.
Clock time is an abstract construction over imperfect measurements and compromises with practicality and it always has been.
[edit to remove under-researched claim about some effects of shifting]
This shows the difference between solar time and standard time. By switching to DST you essentially shift the gradient to the east by an hour.
Other than Greenland I can't see a timezone where that wouldn't mean that the longitude at which the difference is 0 is outside of the actual timezone.
This is a good visualization and gives a qualitative awareness I lacked before. I didn't realize how many timezones in the world are severely "off center" and counter to my own experience. I've lived my whole life in areas that are "barely green" to "slightly pink" in this map. Oddly, most of my travel destinations have also had similar solar alignment, whether in North America, Europe, or Asia. The biggest deviation I have experienced is that of South Korea, which I didn't really notice as unusual during a short visit with jet lag.
It is striking how many timezones are all red instead of being split red and green. In my childhood, people always talked about how different the evening/night culture was in Spain with meals at late hours. This map tells me the difference is less significant than I imagined as far as solar life, and more due to the time standard.
While this topic is beat to death already, I remain torn. On the one hand, centering on solar time is the only logical criteria I can see for adjusting and revising standards. To revise it even further away seems illogical to me. But, the map clearly many cultures already have gone that route. I can imagine many of these deviations came from some legacy desire to synchronize with an adjacent center of power or commerce. I can also appreciate that if we set it far enough out of whack, it illuminates how any standard is inherently arbitrary.
>It is striking how many timezones are all red instead of being split red and green
FWIW, I think that map is from the time when Russia tried permanent DST from 2011 to 2014[1]. They changed to permanent standard time after it proved unpopular.
I took the part a lot of this reply was about out because it was probably wrong.
Regardless, there's no purity to be had here. No matter what, time zones themselves are a compromise for the sake of practicality -- there's no inherent virtue in "the sun is at precisely peak at 12pm +/- a geographic offset."
Clock time is an abstract construction over imperfect measurements and compromises with practicality and it always has been.
[edit to remove under-researched claim about some effects of shifting]