Meaning – Does ‘Notified by [Date]’ Include the End Date?

The phrasing indicates that employment at X began sometime between 1985-01-01 and 1985-12-31, and ended sometime between 1988-01-01 and 1988-12-31.

Best usage would be to use common date notations on a CV, with the dates abutting each other.

For example:

• From 1985 to 1988 he worked at X.
• From 1988 to 1993 he worked at Y.

This describes the broadest outlines of employment, although it does allow for anywhere between a period of unemployment nearly a year long, or almost an entire year's overlap between employers.

People do use the term in both ways (rightly or wrongly), so it is best to examine the context, to help you decide what is meant.

However, without additional information from the context, I would say that the correct meaning is up to but not including.

To express inclusion of the upper boundary, you can use up through instead of up to.

(And I agree with others that there are less ambiguous ways to express ranges and inclusion/exclusion of their limits.)