The data for this infographic comes from Wikidata.
While it took me some time to come up with the easiest approach, it eventually seems best to use a SPARQL query.
After working around it for a bit (and using Wikipedia's great Query service), I came up with this query:
SELECT ?item ?itemLabel ?start_time ?timeprecision WHERE { SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE]". } { SELECT DISTINCT ?item WHERE { ?item wdt:P580 ?start. { ?item (wdt:P31/(wdt:P279*)) wd:Q103495. } UNION { ?item (wdt:P31/(wdt:P279*)) wd:Q8465. } UNION { ?item (wdt:P31/(wdt:P279*)) wd:Q198. } UNION { ?item (wdt:P31/(wdt:P279*)) wd:Q350604. } } } OPTIONAL { ?item p:P580/psv:P580 ?timenode. ?timenode wikibase:timePrecision ?timeprecision. ?timenode wikibase:timeValue ?date. ?item wdt:P580 ?start_time. } FILTER ( ?timeprecision > 10 ) }