diff --git a/embed/sqlite3.wasm b/embed/sqlite3.wasm
index 7f456bb..e2633ef 100755
Binary files a/embed/sqlite3.wasm and b/embed/sqlite3.wasm differ
diff --git a/sqlite3/date.patch b/sqlite3/date.patch
new file mode 100644
index 0000000..4b29c69
--- /dev/null
+++ b/sqlite3/date.patch
@@ -0,0 +1,57 @@
+--- sqlite3.c.orig
++++ sqlite3.c
+@@ -340,6 +340,7 @@ static int setDateTimeToCurrent(sqlite3_context *context, DateTime *p){
+   p->iJD = sqlite3StmtCurrentTime(context);
+   if( p->iJD>0 ){
+     p->validJD = 1;
++    p->tzSet = 1;
+     return 0;
+   }else{
+     return 1;
+@@ -355,6 +356,7 @@ static int setDateTimeToCurrent(sqlite3_context *context, DateTime *p){
+ static void setRawDateNumber(DateTime *p, double r){
+   p->s = r;
+   p->rawS = 1;
++  p->tzSet = 1;
+   if( r>=0.0 && r<5373484.5 ){
+     p->iJD = (sqlite3_int64)(r*86400000.0 + 0.5);
+     p->validJD = 1;
+@@ -572,6 +574,7 @@ static int toLocaltime(
+   time_t t;
+   struct tm sLocal;
+   int iYearDiff;
++  DateTime x;
+ 
+   /* Initialize the contents of sLocal to avoid a compiler warning. */
+   memset(&sLocal, 0, sizeof(sLocal));
+@@ -585,7 +588,7 @@ static int toLocaltime(
+     ** SQLite attempts to map the year into an equivalent year within this
+     ** range, do the calculation, then map the year back.
+     */
+-    DateTime x = *p;
++    x = *p;
+     computeYMD_HMS(&x);
+     iYearDiff = (2000 + x.Y%4) - x.Y;
+     x.Y += iYearDiff;
+@@ -610,8 +613,13 @@ static int toLocaltime(
+   p->validHMS = 1;
+   p->validJD = 0;
+   p->rawS = 0;
++  p->tzSet = 0;
+   p->validTZ = 0;
+   p->isError = 0;
++  x = *p;
++  computeJD(&x);
++  p->tz = (x.iJD-p->iJD)/60000;
++  if( abs(p->tz)>= 900 ) p->tz = 0;
+   return SQLITE_OK;
+ }
+ #endif /* SQLITE_OMIT_LOCALTIME */
+@@ -781,6 +789,7 @@ static int parseModifier(
+           p->validJD = 1;
+           p->tzSet = 1;
+         }
++        p->tz = 0;
+         rc = SQLITE_OK;
+       }
+ #endif
diff --git a/sqlite3/func.c b/sqlite3/func.c
index f6e54f7..550e165 100644
--- a/sqlite3/func.c
+++ b/sqlite3/func.c
@@ -18,14 +18,15 @@ int sqlite3_create_collation_go(sqlite3 *db, const char *zName, void *pApp) {
 int sqlite3_create_function_go(sqlite3 *db, const char *zName, int nArg,
                                int flags, void *pApp) {
   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8 | flags, pApp,
-                                    go_func, NULL, NULL, go_destroy);
+                                    go_func, /*step=*/NULL, /*final=*/NULL,
+                                    go_destroy);
 }
 
 int sqlite3_create_aggregate_function_go(sqlite3 *db, const char *zName,
                                          int nArg, int flags, void *pApp) {
   return sqlite3_create_window_function(db, zName, nArg, SQLITE_UTF8 | flags,
-                                        pApp, go_step, go_final, NULL, NULL,
-                                        go_destroy);
+                                        pApp, go_step, go_final, /*value=*/NULL,
+                                        /*inverse=*/NULL, go_destroy);
 }
 
 int sqlite3_create_window_function_go(sqlite3 *db, const char *zName, int nArg,
diff --git a/sqlite3/progress.c b/sqlite3/progress.c
index 8049ecb..781b1a3 100644
--- a/sqlite3/progress.c
+++ b/sqlite3/progress.c
@@ -5,5 +5,5 @@
 int go_progress(void *);
 
 void sqlite3_progress_handler_go(sqlite3 *db, int n) {
-  sqlite3_progress_handler(db, n, go_progress, NULL);
+  sqlite3_progress_handler(db, n, go_progress, /*arg=*/NULL);
 }
diff --git a/sqlite3/sqlite_cfg.h b/sqlite3/sqlite_cfg.h
index c70982c..e40a8e3 100644
--- a/sqlite3/sqlite_cfg.h
+++ b/sqlite3/sqlite_cfg.h
@@ -5,12 +5,28 @@
 #define SQLITE_OS_OTHER 1
 #define SQLITE_BYTEORDER 1234
 
+#define HAVE_INT8_T 1
+#define HAVE_INT16_T 1
+#define HAVE_INT32_T 1
+#define HAVE_INT64_T 1
+#define HAVE_UINT8_T 1
+#define HAVE_UINT16_T 1
+#define HAVE_UINT32_T 1
+#define HAVE_UINT64_T 1
 #define HAVE_STDINT_H 1
 #define HAVE_INTTYPES_H 1
 
+#define HAVE_LOG2 1
+#define HAVE_LOG10 1
 #define HAVE_ISNAN 1
+
 #define HAVE_USLEEP 1
+#define HAVE_NANOSLEEP 1
+
+#define HAVE_GMTIME_R 1
 #define HAVE_LOCALTIME_S 1
+
+#define HAVE_MALLOC_H 1
 #define HAVE_MALLOC_USABLE_SIZE 1
 
 // Recommended Options
@@ -51,11 +67,11 @@
 #define SQLITE_ENABLE_RTREE 1
 #define SQLITE_ENABLE_GEOPOLY 1
 
+#define SQLITE_SOUNDEX
+
 // Session Extension
 // #define SQLITE_ENABLE_SESSION
 // #define SQLITE_ENABLE_PREUPDATE_HOOK
 
-#define SQLITE_SOUNDEX
-
 // Implemented in vfs.c.
 int localtime_s(struct tm *const pTm, time_t const *const pTime);
\ No newline at end of file
diff --git a/sqlite3/time.c b/sqlite3/time.c
index 75b8744..890c4aa 100644
--- a/sqlite3/time.c
+++ b/sqlite3/time.c
@@ -1,3 +1,4 @@
+#include <stddef.h>
 #include <string.h>
 
 #include "sqlite3.h"
@@ -26,7 +27,63 @@ static int time_collation(void *pArg, int nKey1, const void *pKey1, int nKey2,
   return rc;
 }
 
+static void json_time_func(sqlite3_context *context, int argc,
+                          sqlite3_value **argv) {
+  DateTime x;
+  if (isDate(context, argc, argv, &x)) return;
+  if (x.tzSet && x.tz) {
+    x.iJD += x.tz * 60000;
+    if (!validJulianDay(x.iJD)) return;
+    x.validYMD = 0;
+    x.validHMS = 0;
+  }
+  computeYMD_HMS(&x);
+
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  sqlite3_str *res = sqlite3_str_new(db);
+
+  sqlite3_str_appendf(res, "%04d-%02d-%02dT%02d:%02d:%02d",  //
+                      x.Y, x.M, x.D,                         //
+                      x.h, x.m, (int)(x.iJD / 1000 % 60));
+
+  if (x.useSubsec) {
+    int rem = x.iJD % 1000;
+    if (rem) {
+      sqlite3_str_appendchar(res, 1, '.');
+      sqlite3_str_appendchar(res, 1, '0' + rem / 100);
+      if ((rem %= 100)) {
+        sqlite3_str_appendchar(res, 1, '0' + rem / 10);
+        if ((rem %= 10)) {
+          sqlite3_str_appendchar(res, 1, '0' + rem);
+        }
+      }
+    }
+  }
+
+  if (x.tz) {
+    sqlite3_str_appendf(res, "%+03d:%02d", x.tz / 60, abs(x.tz) % 60);
+  } else {
+    sqlite3_str_appendchar(res, 1, 'Z');
+  }
+
+  int rc = sqlite3_str_errcode(res);
+  if (rc) {
+    sqlite3_result_error_code(context, rc);
+    return;
+  }
+
+  int n = sqlite3_str_length(res);
+  sqlite3_result_text(context, sqlite3_str_finish(res), n, sqlite3_free);
+}
+
 int sqlite3_time_init(sqlite3 *db, char **pzErrMsg,
                       const sqlite3_api_routines *pApi) {
-  return sqlite3_create_collation(db, "time", SQLITE_UTF8, 0, time_collation);
+  sqlite3_create_collation_v2(db, "time", SQLITE_UTF8, /*arg=*/NULL,
+                              time_collation,
+                              /*destroy=*/NULL);
+  sqlite3_create_function_v2(
+      db, "json_time", -1,
+      SQLITE_UTF8 | SQLITE_DETERMINISTIC | SQLITE_INNOCUOUS, /*arg=*/NULL,
+      json_time_func, /*step=*/NULL, /*final=*/NULL, /*destroy=*/NULL);
+  return SQLITE_OK;
 }
\ No newline at end of file
diff --git a/tests/time_test.go b/tests/time_test.go
index 0a8dbda..0b398df 100644
--- a/tests/time_test.go
+++ b/tests/time_test.go
@@ -1,6 +1,7 @@
 package tests
 
 import (
+	"fmt"
 	"reflect"
 	"testing"
 	"time"
@@ -205,3 +206,103 @@ func TestDB_timeCollation(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestDB_jsonTime(t *testing.T) {
+	t.Parallel()
+
+	reference := time.Date(2013, 10, 7, 4, 23, 19, 120_000_000, time.FixedZone("", -4*3600))
+
+	db, err := driver.Open(":memory:", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS times (tstamp)`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = db.Exec(`INSERT INTO times VALUES (?), (?), (?)`,
+		reference,
+		sqlite3.TimeFormatUnixFrac.Encode(reference),
+		sqlite3.TimeFormatJulianDay.Encode(reference))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	rows, err := db.Query(`
+		SELECT
+			json_time(tstamp, 'auto', 'subsec'),
+			json_time(tstamp, 'auto')
+		FROM times`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var t0, t1 time.Time
+		rows.Scan(&t0, &t1)
+		if want := reference; !t0.Equal(want) {
+			t.Errorf("got %v, want %v", t0, want)
+		}
+		if want := reference.Truncate(time.Second); !t1.Equal(want) {
+			t.Errorf("got %v, want %v", t1, want)
+		}
+	}
+}
+
+func TestDB_isoWeek(t *testing.T) {
+	t.Parallel()
+
+	tests := []time.Time{
+		time.Date(1977, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1977, 1, 2, 0, 0, 0, 0, time.UTC),
+		time.Date(1977, 12, 31, 0, 0, 0, 0, time.UTC),
+		time.Date(1978, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1978, 1, 2, 0, 0, 0, 0, time.UTC),
+		time.Date(1978, 12, 31, 0, 0, 0, 0, time.UTC),
+		time.Date(1979, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1979, 1, 2, 0, 0, 0, 0, time.UTC),
+		time.Date(1979, 12, 31, 0, 0, 0, 0, time.UTC),
+		time.Date(1980, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1980, 12, 28, 0, 0, 0, 0, time.UTC),
+		time.Date(1980, 12, 29, 0, 0, 0, 0, time.UTC),
+		time.Date(1980, 12, 30, 0, 0, 0, 0, time.UTC),
+		time.Date(1980, 12, 31, 0, 0, 0, 0, time.UTC),
+		time.Date(1981, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1981, 12, 31, 0, 0, 0, 0, time.UTC),
+		time.Date(1982, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1982, 1, 2, 0, 0, 0, 0, time.UTC),
+		time.Date(1982, 1, 3, 0, 0, 0, 0, time.UTC),
+	}
+
+	db, err := sqlite3.Open(":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	stmt, _, err := db.Prepare(`SELECT strftime('%G-W%V-%u', ?)`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer stmt.Close()
+
+	for _, tm := range tests {
+		stmt.BindTime(1, tm, sqlite3.TimeFormatDefault)
+		if stmt.Step() {
+			y, w := tm.ISOWeek()
+			d := tm.Weekday()
+			if d == 0 {
+				d = 7
+			}
+			want := fmt.Sprintf("%04d-W%02d-%d", y, w, d)
+			if got := stmt.ColumnText(0); got != want {
+				t.Errorf("got %q, want %q (%v)", got, want, tm)
+			}
+		}
+		stmt.Reset()
+	}
+}
diff --git a/vfs/tests/mptest/testdata/mptest.wasm.bz2 b/vfs/tests/mptest/testdata/mptest.wasm.bz2
index f22e2ed..b0061cb 100644
--- a/vfs/tests/mptest/testdata/mptest.wasm.bz2
+++ b/vfs/tests/mptest/testdata/mptest.wasm.bz2
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:c59231ce10786b45be958027d23cffc74894a00120b30c8d3accb26f4182b29a
-size 509312
+oid sha256:25ccdde5ddab41213abda7ecf6dd95c2966acaef5a645f9f35c170a84697556e
+size 509445
diff --git a/vfs/tests/speedtest1/testdata/speedtest1.wasm.bz2 b/vfs/tests/speedtest1/testdata/speedtest1.wasm.bz2
index 31601d9..a776a2e 100644
--- a/vfs/tests/speedtest1/testdata/speedtest1.wasm.bz2
+++ b/vfs/tests/speedtest1/testdata/speedtest1.wasm.bz2
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:9f715bad486eeae35ecb3cf05a2e6265fbfc24a2de0836bdc8fd760510ac1d3a
-size 524127
+oid sha256:4306d2a8c460f24955bb944923837800c887ee4080d725777392b834b7567bab
+size 524003