1diff --git a/src/RawFormulas/Date.ts b/src/RawFormulas/Date.ts
 2index 82e8da4..6369a7e 100644
 3--- a/src/RawFormulas/Date.ts
 4+++ b/src/RawFormulas/Date.ts
 5@@ -51,7 +51,9 @@ var DATEVALUE = function (...values) : number {
 6   var dateNumber;
 7   if (RegExUtil.matchDateStringYearMonthDaySlash(dateString)) { // Check "2012/1/23"
 8     dateNumber = new ExcelDate(moment(dateString, "Y/M/D")).toNumber();
 9-  } if (RegExUtil.matchDateStringMonthDayYearSlash(dateString)) { // Check "1/23/2012"
10+  } else if (RegExUtil.matchDateStringYearMonthDayHyphen(dateString)) { // Check "2012-1-23"
11+    dateNumber = new ExcelDate(moment(dateString, "Y-M-D")).toNumber();
12+  } else if (RegExUtil.matchDateStringMonthDayYearSlash(dateString)) { // Check "1/23/2012"
13     dateNumber = new ExcelDate(moment(dateString, "M/D/Y")).toNumber();
14   }
15   if (dateNumber === undefined) {
16diff --git a/src/RawFormulas/Utils.ts b/src/RawFormulas/Utils.ts
17index 40d8f24..b98d7eb 100644
18--- a/src/RawFormulas/Utils.ts
19+++ b/src/RawFormulas/Utils.ts
20@@ -370,6 +370,7 @@ class RegExUtil {
21   private static MONTH_DAY_YEAR_SLASH_REGEX = /^\s*([1-9]|0[1-9]|1[0-2])\/([1-9]|[0-2][0-9]|3[0-1])\/([1-9][0-9][0-9][0-9])\s*$/;
22   private static DAY_MONTH_YEAR_SLASH_REGEX = /^\s*([1-9]|[0-2][0-9]|3[0-1])\/([1-9]|0[1-9]|1[0-2])\/([1-9][0-9][0-9][0-9])\s*$/;
23   private static YEAR_MONTH_DAY_SLASH_REGEX = /^\s*([1-9][0-9][0-9][0-9])\/([1-9]|0[1-9]|1[0-2])\/([1-9]|[0-2][0-9]|3[0-1])\s*$/;
24+  private static YEAR_MONTH_DAY_HYPHEN_REGEX = /^\s*([1-9][0-9][0-9][0-9])-([1-9]|0[1-9]|1[0-2])-([1-9]|[0-2][0-9]|3[0-1])\s*$/;
25 
26   /**
27    * Match dates in the form "mm/dd/yyyy" or "m/d/yyyy".
28@@ -390,7 +391,7 @@ class RegExUtil {
29   }
30 
31   /**
32-   * Match dates in the form "yyyy/mm/dd" or "yyyy/mm/dd".
33+   * Match dates in the form "yyyy/mm/dd" or "yyyy/m/d".
34    * @param dateString to match
35    * @returns {RegExpMatchArray} matches or null
36    */
37@@ -398,6 +399,15 @@ class RegExUtil {
38     return dateString.match(this.YEAR_MONTH_DAY_SLASH_REGEX);
39   }
40 
41+  /**
42+   * Match dates in the form "yyyy-mm-dd" or "yyyy-m-d".
43+   * @param dateString to match
44+   * @returns {RegExpMatchArray} matches or null
45+   */
46+  static matchDateStringYearMonthDayHyphen(dateString : string) : RegExpMatchArray | null {
47+    return dateString.match(this.YEAR_MONTH_DAY_HYPHEN_REGEX);
48+  }
49+
50 }
51 
52 export {
53diff --git a/tests/FormulasTest.ts b/tests/FormulasTest.ts
54index e263af0..a0586a8 100644
55--- a/tests/FormulasTest.ts
56+++ b/tests/FormulasTest.ts
57@@ -796,7 +796,22 @@ assertEquals(DATEVALUE("1992/1/24"), 33627);
58 assertEquals(DATEVALUE("1992/12/21"), 33959);
59 assertEquals(DATEVALUE("1992/01/31"), 33634);
60 assertEquals(DATEVALUE("1992/1/13"), 33616);
61-
62+// yyyy-m-d
63+assertEquals(DATEVALUE("1992-6-24"), 33779);
64+assertEquals(DATEVALUE("1992-06-24"), 33779);
65+assertEquals(DATEVALUE("1999-1-01"), 36161);
66+assertEquals(DATEVALUE("2222-1-01"), 117610);
67+assertEquals(DATEVALUE("1902-9-02"), 976);
68+assertEquals(DATEVALUE("1902-9-2"), 976);
69+assertEquals(DATEVALUE("4243-11-3"), 856071);
70+assertEquals(DATEVALUE("  1992-04-19  "), 33713);
71+assertEquals(DATEVALUE("1992-5-20"), 33744);
72+assertEquals(DATEVALUE("1992-6-21"), 33776);
73+assertEquals(DATEVALUE("1992-9-29"), 33876);
74+assertEquals(DATEVALUE("1992-1-24"), 33627);
75+assertEquals(DATEVALUE("1992-12-21"), 33959);
76+assertEquals(DATEVALUE("1992-01-31"), 33634);
77+assertEquals(DATEVALUE("1992-1-13"), 33616);
78 
79 
80