Daylight saving time can break schedules quietly

The most dangerous timezone bug is the one that looks correct to one participant and wrong to everyone else.

Review high-risk workflows

Start with systems and processes that depend on wall-clock time:

Test transitions explicitly

Do not assume your libraries or integrations all behave the same way around DST boundaries.

Communicate date-specific changes

When you warn teams about a DST shift, include exact dates and affected regions. Avoid relative wording like "this weekend" in global communication.

Add defensive defaults

Prefer timezone-aware storage, UTC-based scheduling where possible, and UI that always displays the relevant timezone label.

Final check

If a workflow matters to revenue, support, or incident response, simulate the next DST transition before it happens.