The ISO 8601 standard defines formats for representing date-time values as text. The T is just a marker for where the time part begins. The Z is an abbreviation of +00:00 , meaning UTC (an offset of zero hour-minutes-seconds).

Does Z mean expiry date?

The ‘Z’ means UTC. Try not to store local dates. If you want to find a good thread on dates and why you should use UTC check this thread.

What is the Z date on Avon products?

On all Avon products there is a date code on the bottom of the jar (or near the bottom). It is a stamped on or engraved 4 or 5 digit code. This code has the month (as a letter A-L), day of month (A-Z) and year made, and facility is the last number.