When the timestamp is the finding, two filings an hour apart in different capitals tell a different story from two on the same day. The clock behind each filing is a public field, and reading it precisely is what separates a coincidence from a decision.
A reader assessing a set of coordinated filings in two countries, prepared by advisors on opposite sides of a time zone, is not primarily interested in whether each filing arrived by its own local deadline. They are interested in the relative order of the filings on a single timeline.
Registers display timestamps differently. Some display local time without an offset. Some display UTC. Some display the sender's declared time zone. Some retain the submission timestamp separately from the publication timestamp. Aligning a cross-border set requires converting each to a single reference, treating the acknowledgment timestamp as authoritative where available, and preserving the raw display value so the conversion can be checked.
Keep the conversion explicit and store the raw timestamps alongside the converted ones. A narrative that depends on the order of events across time zones has to be defensible against a question about the conversion.