The entry gives the year of the acquisition of the temperature data (which may differ from the year of publication). If the month is unknown use 01, i.e. for the year 2005 use 2005-01. For non-unique time values, define a range in the format: ‘YYYY-MM; YYYY-MM’
What should I do for the date of acquisition if it was not clarified in the … show morepaper (for example if it was given as between the years of 1991-1995, or summers of the 2010-2011-2012 ?