VIP sticker dates

Time to delurk for a bit....

I need to pick the combined minds of UKRS about VIPs to settle an
argument and to satisfy my own curiosity once and for all. Apologies to
anyone who has seen the same question on other lists.

Assuming there are no clues in the sticker wording - should a VIP
sticker be punched out for the date of the O2 inspection/cleaning or for
the date of the *expiry* of the test?

I have checked the documentation from my IANTD Mixer/Blender course and
various websites, but cannot see any clear statement other than a
cylinder needs an in-date VIP sticker to be in oxygen service - nothing
about how to interpret the sticker. Having seen cylinders using both
approaches I can only assume it is the dive shop's discretion how to
interpret the validity.

Cheers

Chris