diff --git a/manifest b/manifest
index 4b7bf71acf..79f5fd15df 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C All\sdate/time\smodifiers\sof\sthe\sform\s(+/-)YYYY-MM-DD\swithout\sthe\sfollowing\nHH:MM:SS.SSS.
-D 2023-05-30T11:13:56.499
+C New\stest\scases\sfor\sthe\stimediff\senhancements.
+D 2023-05-30T11:51:45.702
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -1605,7 +1605,7 @@ F test/threadtest3.c 655bff6c0895ec03f014126aa65e808fac9aae8c5a7a7da58a510cbe8b4
 F test/threadtest4.c c1e67136ceb6c7ec8184e56ac61db28f96bd2925
 F test/threadtest5.c 9b4d782c58d8915d7e955ff8051f3d03628bda0d33b82971ea8c0f2f2808c421
 F test/time-wordcount.sh 8e0b0f8109367827ad5d58f5cc849705731e4b90
-F test/timediff1.test ff10ea5829bbe7d11c3c9bed75f8cba1cf42b3c23bd68c4f9d6ef8868546eb85
+F test/timediff1.test 635b0e1857d1a3519382ae1a0aff9580c33e550c5a5cbec600b5edd2e0487018
 F test/tkt-02a8e81d44.test 6c80d9c7514e2a42d4918bf87bf6bc54f379110c
 F test/tkt-18458b1a.test 6a62cb1ee50fa3c620da59e3a6f531eb38fceaf7e2166203816b724524e6f1d6
 F test/tkt-26ff0c2d1e.test c15bec890c4d226c0da2f35ff30f9e84c169cfef90e73a8cb5cec11d723dfa96
@@ -2072,8 +2072,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P cff293b0a79107def7bfe54fd60ac4a721c5098c85229d9b46a4e2c4cbf34a6a
-R 0943b555654140e47681c2f446f6eb02
+P fa9237a8ab803ca3f67fe753516b7bdb98be3d625e8e241ddf9b02509210e225
+R 51c5fa7aa16d0c81c327481e1cc4975e
 U drh
-Z 8e551011a7166e1e39c03f9c16d64816
+Z dfeb1c0c465184df485198331681092e
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index b0c280008f..370e1dd09f 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-fa9237a8ab803ca3f67fe753516b7bdb98be3d625e8e241ddf9b02509210e225
\ No newline at end of file
+f14633ce6ddf28a14b03e2da623d96e439966aa3fc30c26cb0be59c0e15b3e9c
\ No newline at end of file
diff --git a/test/timediff1.test b/test/timediff1.test
index 07d50713f6..79000af1d4 100644
--- a/test/timediff1.test
+++ b/test/timediff1.test
@@ -88,26 +88,62 @@ set p1 {
   7   {2050-05-29 14:26}
 }
 set p2 {
-  A   {1900-02-28 11:00}
-  B   {1900-03-01 12:00}
-  C   {2000-02-29 13:00}
-  D   {2005-04-30 23:59:59}
-  E   {2005-05-01}
-  F   {1066-10-14}
-  G   {1904-02-29 11:25}
+  A   {1066-10-14}
+  B   {1900-02-28 11:00}
+  C   {1900-03-01 12:00}
+  D   {1904-02-29 11:25}
+  E   {2000-02-29 13:00}
+  E   {2000-03-01 14:00}
+  F   {2001-03-31 15:15}
+  G   {2002-04-01 16:59}
+  H   {2003-04-30 17:00}
+  I   {2004-05-01 23:59:59}
+  J   {2005-06-01}
+  K   {2006-06-30 01:23:45}
+  L   {2007-12-31 02:00}
+  M   {2008-01-01 01:59}
 }
 
 foreach {x1 d1} $p1 {
   foreach {x2 d2} $p2 {
-    set r1 [db one {SELECT datetime($d1,'auto')}]
+    set r1 [db one {SELECT datetime($d1)}]
     do_execsql_test timediff-4-$x1$x2 {
-      SELECT datetime($d2, 'auto', timediff($d1,$d2));
+      SELECT datetime($d2, timediff($d1,$d2));
     } [list $r1]
-    set r2 [db one {SELECT datetime($d2,'auto')}]
+    set r2 [db one {SELECT datetime($d2)}]
     do_execsql_test timediff-4-$x2$x1 {
-      SELECT datetime($d1, 'auto', timediff($d2,$d1));
+      SELECT datetime($d1, timediff($d2,$d1));
     } [list $r2]
   }
 }
 
+# Partial time-diffs as modifiers
+#
+datetest 5-1 {datetime('2000-01-01','+0001-02-03')} {2001-03-04 00:00:00}
+datetest 5-2 {datetime('2000-01-01','+0001-02-03x')} {NULL}
+datetest 5-3 {datetime('2000-01-01','+0001-11-03')} {2001-12-04 00:00:00}
+datetest 5-4 {datetime('2000-01-01','+0001-12-03')} {NULL}
+datetest 5-5 {datetime('2000-01-01','+0001-02-30')} {2001-03-31 00:00:00}
+datetest 5-6 {datetime('2000-01-01','+0001-02-31')} {NULL}
+datetest 5-7 {datetime('2000-01-01','+0001-02-03 0')} {NULL}
+datetest 5-8 {datetime('2000-01-01','+0001-02-03 01')} {NULL}
+datetest 5-9 {datetime('2000-01-01','+0001-02-03 01:')} {NULL}
+datetest 5-10 {datetime('2000-01-01','+0001-02-03 01:0')} {NULL}
+datetest 5-11 {datetime('2000-01-01','+0001-02-03 01:02')} {2001-03-04 01:02:00}
+datetest 5-12 {datetime('2000-01-01','+0001-02-03 01:02:')} {NULL}
+datetest 5-13 {datetime('2000-01-01','+0001-02-03 01:02:0')} {NULL}
+datetest 5-14 {datetime('2000-01-01','+0001-02-03 01:02:03')} \
+                                                   {2001-03-04 01:02:03}
+datetest 5-15 {datetime('2000-01-01','+0001-02-03 01:02:03.')} NULL
+datetest 5-16 {datetime('2000-01-01','+0001-02-03 01:02:03.5')} \
+                                                   {2001-03-04 01:02:03}
+datetest 5-17 {datetime('2000-01-01','+0001-02-03 01:02:03.50')} \
+                                                   {2001-03-04 01:02:03}
+datetest 5-18 {datetime('2000-01-01','+0001-02-03 01:02:03.500')} \
+                                                   {2001-03-04 01:02:03}
+datetest 5-19 {datetime('2000-01-01','+0001-02-03 01:02:03.500x')} {NULL}
+datetest 5-20 {datetime('2000-01-01','+0001-02-03 01:02:03.500 x')} {NULL}
+
+
+
 finish_test