"EDTF Level","Section","Example pattern","Example","EDTF notes/interpretation","Islandora pattern","Islandora notes","edtf example order","Islandora sort order"
"0","Date","####-##-##","1985-04-12",,"1985-04-12",,"1","18.5"
"0","Date","####-##","1985-04",,"1985-04",,"2","14.5"
"0","Date","####","2004",,"2004",,"3","27"
"0","Date and Time","####-##-##T##:##:##","1985-04-12T23:20:30",,,"Do not use. Support for time level of granularity not expected in near future in current or new Islandora","4",
"0","Date and Time","####-##-##T##:##:##Z","1985-04-12T23:20:30Z",,,"Do not use. Support for time level of granularity not expected in near future in current or new Islandora","5",
"0","Date and Time","####-##-##T##:##:##-##","1985-04-12T23:20:30-04",,,"Do not use. Support for time level of granularity not expected in near future in current or new Islandora","6",
"0","Date and Time","####-##-##T##:##:##+##:##","1985-04-12T23:20:30+04:30",,,"Do not use. Support for time level of granularity not expected in near future in current or new Islandora","7",
"0","Time Interval","####/####","2004/2005",,"2004 - 2005",,"8","28"
"0","Time Interval","####-##/####-##","2004-06/2006-08",,"2004-06 - 2006-08",,"9","38"
"0","Time Interval","####-##-##/####-##-##","2004-02-01/2005-02-08",,"2004-02-01 - 2005-02-08",,"10","34"
"0","Time Interval","####-##-##/####-##","2004-02-01/2005-02",,"2004-02-01 - 2005-02",,"11","33"
"0","Time Interval","####-##-##/####","2004-02-01/2005",,"2004-02-01 - 2005",,"12","32"
"0","Time Interval","####/####-##","2005/2006-02",,"2005 - 2006-02",,"13","41"
"1","Letter-prefixed calendar year","Y######","Y170002",,,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates longer than 4 years long in your data.","14",
"1","Letter-prefixed calendar year","Y-######","Y-170002",,,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates longer than 4 years long in your data.","15",
"1","Seasons","####-##","2004-21","Allowed season values: 21 (spring), 22 (summer), 23 (fall), 24 (winter)","2004 Spring",,"16","30"
"1","Qualification of date (complete)","####?","2003?","uncertain","2003 (uncertain)",,"17","26"
"1","Qualification of date (complete)","####-##~","2004-06~","approximate","2004-06 (approximate)",,"18","36"
"1","Qualification of date (complete)","####-##%","2004-06%","uncertain and approximate","2004-06 (uncertain and approximate)",,"19","37"
"1","Unspecified digit(s) from the right","###X","200X",,"2000 - 2009 (exact year unspecified)",,"20","23.5"
"1","Unspecified digit(s) from the right","##XX","20XX",,"2000 - 2099 (exact year unspecified)",,"21","24"
"1","Unspecified digit(s) from the right","####-XX","2004-XX",,,"Do not use. Not currently supported. If only year is known just record ‘2004’. Contact LYRASIS if you have a specific use case for this format","22",
"1","Unspecified digit(s) from the right","####-##-XX","1985-04-XX",,,"Do not use. Not currently supported. If only year and month are known just record ‘1985-04’. Contact LYRASIS if you have a specific use case for this format","23",
"1","Unspecified digit(s) from the right","####-XX-XX","1985-XX-XX",,,"Do not use. Not currently supported. If only year is known just record ‘1985’. Contact LYRASIS if you have a specific use case for this format","24",
"1","Open end time interval","####-##-##/..","1985-04-12/..","interval starting at 1985 April 12th with day precision; end open","1985-04-12 to present",,"25","20"
"1","Open end time interval","####-##/..","1985-04/..","interval starting at 1985 April with month precision; end open","1985-04 to present",,"26","16"
"1","Open end time interval","####/..","1985/..","interval starting at year 1985 with year precision; end open","1985 to present",,"27","12"
"1","Open start time interval","../####-##-##","../1985-04-12","interval with open start; ending 1985 April 12th with day precision","1985-04-12 to beginning of time",,"28","19"
"1","Open start time interval","../####-##","../1985-04","interval with open start; ending 1985 April with month precision","1985-04 to beginning of time",,"29","15"
"1","Open start time interval","../####","../1985","interval with open start; ending at year 1985 with year precision","1985 to beginning of time",,"30","11"
"1","Time interval with unknown end","####-##-##/","1985-04-12/","interval starting 1985 April 12th with day precision; end unknown","1985-04-12 to unknown later date",,"31","23"
"1","Time interval with unknown end","####-##/","1985-04/","interval starting 1985 April with month precision; end unknown","1985-04 to unknown later date",,"32","18"
"1","Time interval with unknown end","####/","1985/","interval starting year 1985 with year precision; end unknown","1985 to unknown later date",,"33","14"
"1","Time interval with unknown start","/####-##-##","/1985-04-12","interval with unknown start; ending 1985 April 12th with day precision","1985-04-12 to unknown earlier date",,"34","22"
"1","Time interval with unknown start","/####-##","/1985-04","interval with unknown start; ending 1985 April with month precision","1985-04 to unknown earlier date",,"35","17"
"1","Time interval with unknown start","/####","/1985","interval with unknown start; ending year 1985 with year precision","1985 to unknown earlier date",,"36","13"
"1","Negative calendar year","-####","-1985",," 1986 BCE","IMPORTANT: value begins with a space NOTE: the 1986 is no typo. -1985 indicates 1986 BCE. Humans count backward from 1 CE to 1 BCE. There is no Year 0. Computers cannot skip 0, and so understand 1 BCE to be Year 0. This makes EDTF -1 equivalent to 2 BCE and so on. LIMITATION: All the BCE years will come before the CE dates, but sorting cannot handle treating larger intervals as earlier for BCE and later for CE. Because the sort dates get stored as strings (not numbers) in I7, -1985 comes before -2001 in an ascending date sort, so using the negative sign does not fix this","37","1"
"2","Exponential year","Y-##E#","Y-17E7","the calendar year -17*10 to the seventh power= -170000000",,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates longer than 4 years long in your data.","38",
"2","Significant digits","####S#","1950S2","“some year between 1900 and 1999, estimated to be 1950”",,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates longer than 4 years long in your data.","39",
"2","Significant digits","Y#########S#","Y171010000S3","“some year between 171010000 and 171010999, estimated to be 171010000”",,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates longer than 4 years long in your data.","40",
"2","Significant digits","Y####E#S#","Y3388E2S3","“some year between 338000 and 338999, estimated to be 338800”",,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates longer than 4 years long in your data.","41",
"2","Sub-year groupings","####-##","2001-34","Quarter 1 of 2001; extends Level 1’s Seasons to 21-41","2001 Quarter 2","Record the value given in EDTF standard for each allowed number. Omit parenthetical info.","42","25"
"2","One of a set","[####,####,####..####]","[1667,1668,1670..1672]","One of the years 1667, 1668, 1670, 1671, 1672","1667, 1668, 1670, 1671, or 1672","NOTE: there is no equivalent to EDTF’s .. here. Please list all dates in the set individually","43","4"
"2","One of a set","[####,####]","[1667,1670]","One of the years 1667 or 1670","1667 or 1670",,,"4.5"
"2","One of a set","[..####-##-##]","[..1760-12-03]","December 3, 1760; or some earlier date","1760-12-03 or an earlier date",,"44","7"
"2","One of a set","[####-##..]","[1760-12..]","December 1760, or some later month","1760-12 or a later date",,"45","6"
"2","One of a set","[####-##,####-##,####-##..]","[1760-01,1760-02,1760-12..]","January or February of 1760 or December 1760 or some later month","1760-01, 1760-02, 1760-12, or a later date",,"46","5"
"2","One of a set","[####,####-##]","[1667,1760-12]","Either the year 1667 or the month December of 1760","1667 or 1760-12",,"47","2"
"2","One of a set","[..####]","[..1984]","The year 1984 or an earlier year","1984 or an earlier date",,"48","10"
"2","All Members","{####,####,####..####}","{1667,1668,1670..1672}","All of the years 1667, 1668, 1670, 1671, 1672","1667, 1668, 1670, 1671, and 1672","NOTE: there is no equivalent to EDTF’s .. here. Please list all dates in the set individually","49","3"
"2","All Members","{####,####-##}","{1960,1961-12}","The year 1960 and the month December of 1961","1960 and 1961-12",,"50","8"
"2","All Members","{..####}","{..1984}","The year 1984 and all earlier years","1984 and all earlier years","Or “1984-04 and all previous months” or “1984-04-05 and all previous days”","51","9"
"2","Group qualifiication","####-##-##%","2004-06-11%","year, month, and day uncertain and approximate","2004-06-11 (uncertain and approximate)",,"52","39"
"2","Group qualifiication","####-##~-##","2004-06~-11","year and month approximate, day is certain","2004-06-11 (year and month approximate)",,"53","39.2"
"2","Group qualifiication","####?-##-##","2004?-06-11","year uncertain, but month and day are certain","2004-06-11 (year uncertain)",,"54","39.3"
"2","Qualification of Individual Component","?####-##-~##","?2004-06-~11","year uncertain; month certain; day approximate","2004-06-11 (year uncertain; day approximate)",,"55","39.4"
"2","Qualification of Individual Component","####-%##-##","2004-%06-11","month uncertain and approximate; year and day certain","2004-06-11 (month uncertain and approximate)",,"56","39.1"
"2","Unspecified digit","XXXX","XXXX","undated/unknown date – explicitly records that date research has been done (to whatever extent local policy requires) and no date can be determined. This is considered different than simply leaving the date element blank, since if the element is blank there is no way to know if it was accidentally not filled in, the date research hasn't been done yet, or if there's no date information available","no date recorded",,"n/a","42"
"2","Unspecified digit","###X-##-##","156X-12-25","December 25 sometime during the 1560s",,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates using this pattern.","57",
"2","Unspecified digit","##XX-##-##","15XX-12-25","December 25 sometime during the 1500s",,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates using this pattern.","58",
"2","Unspecified digit","XXXX-##-XX","XXXX-12-XX","Some day in December in some year",,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates using this pattern.","59",
"2","Unspecified digit","#XXX-XX","1XXX-XX","Some month during the 1000s",,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates using this pattern.","60",
"2","Unspecified digit","#XXX-##","1XXX-12","Some December during the 1000s",,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates using this pattern.","61",
"2","Unspecified digit","####-#X","1984-1X","October, November, or December 1984",,"Do not use. Not currently supported. Contact LYRASIS if you need to represent dates using this pattern.","62",
"2","Interval","####-##-~##/####-##-~##","2004-06-~01/2004-06-~20","An interval in June 2004 beginning approximately the first and ending approximately the 20th","2004-06-01 (day approximate) to 2004-06-20 (day approximate)",,"63","38.5"
"2","Interval","####-##-XX/####-##-##","2004-06-XX/2004-07-03","An interval beginning on an unspecified day in June 2004 and ending July 3 2004.",,"Do not use. If possible, record “2004-06 to 2004-07-03” instead. Contact LYRASIS if you have a use case for this specific date pattern.","64",