Does re-importing exported LeetCode submission timestamps preserve original dates or are they treated as new submissions?

LeetCode’s Account Settings include an "Export Data" feature that produces a JSON file containing a user’s submission history, including timestamps, language, code snippets, and verdicts. The platform does not provide an official import or restore function, so users who wish to recover their data must manually re‑submit the saved code via the web interface or API. When doing so, it is unclear whether the platform retains the original submission timestamps from the exported JSON or assigns the current time, which directly influences streak counters, duplicate‑submission checks, and contest rating adjustments.

The uncertainty stems from the lack of documented behavior for manually re‑imported submissions and the potential side‑effects on longitudinal metrics.

• Does LeetCode preserve the original timestamp when a submission is re‑uploaded from exported data?
• If the timestamp is preserved, how does the platform treat the submission with respect to streak calculation and duplicate detection?
• If the timestamp is replaced by the current time, what impact does this have on historical streaks and contest rating recalculations?