diff --git a/OpenChange/NSString+MAPIStore.m b/OpenChange/NSString+MAPIStore.m
index 83ca8d6e6..647eb79f1 100644
--- a/OpenChange/NSString+MAPIStore.m
+++ b/OpenChange/NSString+MAPIStore.m
@@ -24,8 +24,10 @@
 #include <stdbool.h>
 
 #import <Foundation/NSData.h>
+#import <Foundation/NSCalendarDate.h>
 
 #import "NSString+MAPIStore.h"
+#import "NSDate+MAPIStore.h"
 
 #undef DEBUG
 #include <talloc.h>
@@ -67,6 +69,16 @@
   return unicode;
 }
 
+- (struct FILETIME *) asFileTimeInMemCtx: (void *) memCtx
+{
+  NSCalendarDate *d;
+
+  d = [NSCalendarDate dateWithString: self
+                      calendarFormat: @"%Y-%m-%d %H:%M:%S %Z"];
+
+  return [d asFileTimeInMemCtx: memCtx];
+}
+
 - (char) _decodeHexByte: (char) byteChar
 {
   char newByte;