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To extract dates from a geopoints file/variable, use the dates()
Macro function. Try it on the supplied geopoints file to see what it returns.
BUFR
The easiest way to extract dates from a BUFR file is to convert it to geopoints using the Observation Filter and then extract the dates from the resulting geopoints.
Other formats
Extracting dates from other formats can be more tricky and will not be covered here.
Extra Work
If you have time, try the following.