I want to know the answer to the following question:
What usually changes when a place observes DST?
All the background I'm provided with is that "In the United Kingdom, the standard term for UK time when advanced by one hour is British Summer Time (BST), and British English typically inserts summer into other time zone names, e.g. Central European Time (CET) becomes Central European Summer Time (CEST).". Is that enough to answer the question?
Answer: no