Index: src/OFDate.m
==================================================================
--- src/OFDate.m
+++ src/OFDate.m
@@ -124,11 +124,11 @@
 	struct tm tm;
 
 	if (gmtime_r(&sec, &tm) == NULL)
 		@throw [OFOutOfRangeException newWithClass: isa];
 
-	strftime(str, 20, "%Y-%m-%d %H:%M:%S", &tm);
+	strftime(str, 20, "%Y-%m-%dT%H:%M:%S", &tm);
 #else
 	struct tm *tm;
 
 # ifdef OF_THREADS
 	[mutex lock];
@@ -136,11 +136,11 @@
 	@try {
 # endif
 		if ((tm = gmtime(&sec)) == NULL)
 			@throw [OFOutOfRangeException newWithClass: isa];
 
-		strftime(str, 20, "%Y-%m-%d %H:%M:%S", tm);
+		strftime(str, 20, "%Y-%m-%dT%H:%M:%S", tm);
 # ifdef OF_THREADS
 	} @finally {
 		[mutex unlock];
 	}
 # endif

Index: src/OFFile.h
==================================================================
--- src/OFFile.h
+++ src/OFFile.h
@@ -13,10 +13,11 @@
 
 #import "OFSeekableStream.h"
 
 @class OFString;
 @class OFArray;
+@class OFDate;
 
 /**
  * \brief A class which provides functions to read, write and manipulate files.
  */
 @interface OFFile: OFSeekableStream
@@ -89,10 +90,15 @@
  *
  * \param path The new directory to change to
  */
 + (void)changeToDirectory: (OFString*)path;
 
+/**
+ * \return The date of the last modification of the file
+ */
++ (OFDate*)modificationDateOfFile: (OFString*)path;
+
 /**
  * Changes the mode of a file.
  *
  * Only changes read-only flag on Windows.
  *

Index: src/OFFile.m
==================================================================
--- src/OFFile.m
+++ src/OFFile.m
@@ -27,10 +27,11 @@
 
 #import "OFFile.h"
 #import "OFString.h"
 #import "OFArray.h"
 #import "OFThread.h"
+#import "OFDate.h"
 #import "OFAutoreleasePool.h"
 #import "OFExceptions.h"
 #import "macros.h"
 
 #ifdef _WIN32
@@ -390,10 +391,24 @@
 		@throw [OFChangeFileModeFailedException newWithClass: self
 								path: path
 								mode: mode];
 #endif
 }
+
++ (OFDate*)modificationDateOfFile: (OFString*)path
+{
+	struct stat s;
+
+	if (stat([path cString], &s) == -1)
+		/* FIXME: Maybe use another exception? */
+		@throw [OFOpenFileFailedException newWithClass: self
+							  path: path
+							  mode: @"r"];
+
+	/* FIXME: We could be more precise on some OSes */
+	return [OFDate dateWithTimeIntervalSince1970: s.st_mtime];
+}
 
 #ifndef _WIN32
 + (void)changeOwnerOfFile: (OFString*)path
 		  toOwner: (OFString*)owner
 		    group: (OFString*)group

Index: tests/OFDateTests.m
==================================================================
--- tests/OFDateTests.m
+++ tests/OFDateTests.m
@@ -31,12 +31,12 @@
 	TEST(@"+[dateWithTimeIntervalSince1970:microseconds:",
 	    (d2 = [OFDate dateWithTimeIntervalSince1970: 3600 * 25 + 5
 					   microseconds: 1]))
 
 	TEST(@"-[description]",
-	    [[d1 description] isEqual: @"1970-01-01 00:00:00Z"] &&
-	    [[d2 description] isEqual: @"1970-01-02 01:00:05.000001Z"])
+	    [[d1 description] isEqual: @"1970-01-01T00:00:00Z"] &&
+	    [[d2 description] isEqual: @"1970-01-02T01:00:05.000001Z"])
 
 	TEST(@"-[isEqual:]",
 	    [d1 isEqual: [OFDate dateWithTimeIntervalSince1970: 0]] &&
 	    ![d1 isEqual: [OFDate dateWithTimeIntervalSince1970: 0
 						   microseconds: 1]])