Fixed issue in formula match

EPPlus/FormulaParsing/ExcelUtilities/ValueMatcher.cs

@@ -29,9 +29,6 @@
  * Mats Alm   		                Added       		        2013-03-01 (Prior file history on https://github.com/swmal/ExcelFormulaParser)
  *******************************************************************************/
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 
 namespace OfficeOpenXml.FormulaParsing.ExcelUtilities
 {
@@ -52,14 +49,18 @@ public virtual int IsMatch(object o1, object o2)
             {
                 return CompareStringToString(o1.ToString().ToLower(), o2.ToString().ToLower());
             }
-            else if( o1.GetType() == typeof(string))
+            else if (o1.GetType() == typeof(string))
             {
                 return CompareStringToObject(o1.ToString(), o2);
             }
             else if (o2.GetType() == typeof(string))
             {
                 return CompareObjectToString(o1, o2.ToString());
             }
+            else if (o1.GetType() == typeof(DateTime))
+            {
+                return CompareDatetimeToDouble(o1, o2.ToString());
+            }
             return Convert.ToDouble(o1).CompareTo(Convert.ToDouble(o2));
         }
 
@@ -116,5 +117,15 @@ protected virtual int CompareObjectToString(object o1, string o2)
             }
             return IncompatibleOperands;
         }
+
+        protected virtual int CompareDatetimeToDouble(object o1, string o2)
+        {
+            double dt1;
+            if (double.TryParse(o2, out dt1))
+            {
+                return DateTime.FromOADate(double.Parse(o2)).CompareTo(o1);
+            }
+            return IncompatibleOperands;
+        }
     }
 }

EPPlusTest/FormulaParsing/ExcelUtilities/ValueMatcherTests.cs

@@ -103,5 +103,14 @@ public void ShouldReturnMînus2WhenTypesDifferAndStringConversionToDoubleFails()
             var result = _matcher.IsMatch(o1, o2);
             Assert.AreEqual(-2, result);
         }
+
+        [TestMethod]
+        public void ShouldReturnMinus1WhenTypesAreDateTimeAndDouble()
+        {
+            object o1 = Convert.ToDateTime("18/01/2024");
+            object o2 = 41711;
+            var result = _matcher.IsMatch(o1, o2);
+            Assert.AreEqual(-1, result);
+        }
     }
 }