Write a debugging guide in a {{tone}} tone for {{target_audience}}. Include a bug report template, a 5-step diagnostic process (isolate, gather evidence, root cause analysis, implement fix, prevent recurrence), and the top 10 common timezone handling pitfalls in Dart. Keep under 1800 words. Use plain language. If a specific cause cannot be determined with high confidence, skip that section. Paste any relevant background information after these instructions before running.