World Metrology Day
Marked on 20 May each year to highlight the science of measurement and the anniversary of the Metre Convention of 1875.
- UK
- USA
- Ireland (not marked)
- Canada (not marked)
- Australia (not marked)
- New Zealand (not marked)
- International
OrganiserBIPM and OIML
ListingAdded by us from official sources
Last checked19 October 2026
First heldNot known
About the day
World Metrology Day is run jointly by the International Bureau of Weights and Measures and the International Organization of Legal Metrology. It marks the signing of the Metre Convention on 20 May 1875 and has a new theme each year.
2026 theme
Metrology: Building Trust in Policy Making
The 2027 theme has not been announced yet.
Dates for the next three years
| Year | Date | Where | Status |
|---|---|---|---|
| 2027 | Thursday 20 May 2027 | UK, USA, International | Same date every year |
| 2028 | Saturday 20 May 2028 | UK, USA, International | Same date every year |
| 2029 | Sunday 20 May 2029 | UK, USA, International | Same date every year |
Where this information comes from
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