The useful starting point
A message saying next Friday can become ambiguous when it is forwarded or read later. A numerical date can also be interpreted differently across regions. The reader may need a date, time and time zone rather than a relative phrase.
A small step to try
Write the date in a clear form suitable for your audience, and include the time zone when it affects the action. Label whether it is the event date, publication date or response deadline. Check that the timing matches the actual agreement. Clear wording cannot create a deadline that was never set, so keep your evidence separate from the convenience of a concise sentence.