diff --git a/contrib/multiuser_tweaks/timetagger_multiuser_tweaks.py b/contrib/multiuser_tweaks/timetagger_multiuser_tweaks.py
new file mode 100755
index 00000000..2227d8aa
--- /dev/null
+++ b/contrib/multiuser_tweaks/timetagger_multiuser_tweaks.py
@@ -0,0 +1,345 @@
+#!/usr/bin/env python3
+
+"""
+Some utilities to help running TimeTagger in a multi-user environment.
+
+Examples:
+* multiuser_tweaks.py records --merge --dest newuser
+  * merges TimeTagger record tables of multiple users into one user database,
+    replacing the existing records. Extends the records by user information.
+    This can be used to create a timetagger view of the records of multiple users.
+* multiuser_tweaks.py settings --settings settings.json
+  * copy settings from a JSON file to the users settings database tables.
+
+Author: joerg.steffens@bareos.com
+"""
+
+import argparse
+import binascii
+import json
+import logging
+import pathlib
+from pprint import pprint, pformat  # noqa
+import sys
+import time
+
+from itemdb import ItemDB
+from timetagger.server._utils import user2filename, filename2user, ROOT_USER_DIR
+
+
+def setup_parser():
+    """setup argument parsing"""
+    epilog = """%(prog)s is a helper tool for TimeTagger in multi-user environments.
+    TimeTagger uses a separate Sqlite database per user.
+    This tool directly accesses the databases and offers to manipulate them.
+    Especially it can merge the records of multiple users
+    into one user database, replacing the existing records.
+    Every newly generated record is extended by the tag '#user/<username>'.
+    This way each record still show to which user it belongs.
+    """
+
+    argparser = argparse.ArgumentParser(
+        description="Perform actions on TimeTagger databases.",
+        epilog=epilog,
+    )
+    argparser.add_argument(
+        "-d", "--debug", action="store_true", help="enable debugging output"
+    )
+
+    subparsers = argparser.add_subparsers()
+
+    # users
+    parser_users = subparsers.add_parser("users")
+    parser_users.add_argument(
+        "--list", action="store_true", help="show all available user databases"
+    )
+    parser_users.set_defaults(parser=parser_users, func=handle_users_command)
+
+    # records
+    parser_records = subparsers.add_parser(
+        "records",
+        description="Perform action on the records tables of TimeTagger databases.",
+    )
+    parser_records.add_argument(
+        "--dump", action="store_true", help="dump records of user databases"
+    )
+    records_merge_group = parser_records.add_argument_group("merging")
+    records_merge_group.add_argument(
+        "--merge",
+        action="store_true",
+        help="merge source user database records into dest_user records, overwriting all existing records",
+    )
+    records_merge_group.add_argument(
+        "--dest",
+        metavar="dest_user",
+        default="tt_all",
+        help="destination user database (default: '%(default)s')",
+    )
+    records_merge_group.add_argument(
+        "--replace",
+        action="append",
+        help="Replace text entries. The format is '/original_text/replacement_text/'. You can use other separators instead of '/'. This parameter can be given multiple times.",
+    )
+    parser_records.add_argument(
+        "source_user", nargs="*", help="source user (default: <all>)"
+    )
+    parser_records.set_defaults(parser=parser_records, func=handle_records_command)
+
+    # settings
+    parser_settings = subparsers.add_parser(
+        "settings",
+        description="Perform action on the settings tables of TimeTagger databases.",
+    )
+    parser_settings.add_argument(
+        "--dump", action="store_true", help="dump settings from user databases"
+    )
+    parser_settings.add_argument(
+        "--source",
+        help='copy settings from JSON file into user settings databases. Format: { "key1": "value1", "key2": "value2" [, ...] }',
+        type=argparse.FileType("r"),
+        metavar="<filename.json>",
+    )
+    parser_settings.add_argument(
+        "--force", action="store_true", help="overwrite existing user settings"
+    )
+    parser_settings.add_argument(
+        "dest",
+        metavar="dest_user",
+        nargs="*",
+        help="destination user database (default: '<all_users>')",
+    )
+    parser_settings.set_defaults(parser=parser_settings, func=handle_settings_command)
+
+    return argparser
+
+
+def itemdb_exists(db, table):
+    if db.mtime < 0:
+        return False
+    if table not in db.get_table_names():
+        return False
+    return True
+
+
+def get_translation_table(replace):
+    if replace is None:
+        return None
+    table = {}
+    for i in replace:
+        sep = i[0]
+        strings = i.split(sep)
+        if len(strings) != 4 or len(strings[0]) != 0 or len(strings[3]) != 0:
+            raise ValueError(
+                f"Replacement string ('{i}') has an invalid form. Use '/original_text/replacement_text/'. You can use other separators instead of '|'."
+            )
+        table[strings[1]] = strings[2]
+    return table
+
+
+class TimeTaggerDB:
+    def get_timetagger_usernames(self, exclude_users=None):
+        logger = logging.getLogger()
+        logger.debug("ROOT_USER_DIR: %s", ROOT_USER_DIR)
+        ignore_usernames = ["defaultuser"]
+        if exclude_users:
+            ignore_usernames += exclude_users
+        for filename in pathlib.Path(ROOT_USER_DIR).glob("*.db"):
+            try:
+                username = filename2user(filename)
+                if username in ignore_usernames:
+                    logger.debug("skipping username '%s'", username)
+                else:
+                    logger.debug("db: %s, user: %s", filename, username)
+                    yield username
+            except binascii.Error:
+                logger.warning(
+                    "failed to extract username from filename '%s', skipped.", filename
+                )
+
+    def dump_db_by_usernames(self, usernames, table):
+        for username in usernames:
+            self.dump_db_by_username(username, table)
+
+    def dump_db_by_username(self, username, table):
+        print()
+        print(f"username: {username}")
+        filename = user2filename(username)
+        return self.dump_db_by_filename(filename, table)
+
+    def dump_db_by_filename(self, filename, table):
+        print(f"filename: {filename}")
+        db = ItemDB(filename)
+        if not itemdb_exists(db, table):
+            print("database: not existant")
+            return
+        self.dump_db(db, table)
+
+    def dump_db(self, db, table):
+        with db:
+            for i in db.select_all(table):
+                print(i)
+
+
+class Settings(TimeTaggerDB):
+    TABLE = "settings"
+
+    def __init__(self, dest_usernames=None):
+        self.logger = logging.getLogger()
+        if dest_usernames:
+            self.dest_usernames = dest_usernames
+        else:
+            self.dest_usernames = self.get_timetagger_usernames()
+
+    def dump(self):
+        self.dump_db_by_usernames(self.dest_usernames, self.TABLE)
+
+    def distribute_to_user(self, username, settings, force):
+        db_filename = user2filename(username)
+        db = ItemDB(db_filename)
+        if not itemdb_exists(db, self.TABLE):
+            print("  skipped, database (table) does not exists")
+            return
+        now = int(time.time())
+        with db:
+            for key, value in settings.items():
+                print(f"  '{key}': ", end="")
+                result = db.select_one(self.TABLE, "key = ?", key)
+                if key == "tag_presets":
+                    current_set = set()
+                    if result:
+                        current_set = set(result.get("value"))
+                    new_set = set(value)
+                    if new_set <= current_set:
+                        print("skipped (values already set)")
+                        continue
+                    print("adding: ", list(new_set - current_set))
+                    value = list(current_set | new_set)
+                    db.put_one(self.TABLE, key=key, value=value, st=now, mt=now)
+                elif result and not force:
+                    print("skipped (already set)")
+                else:
+                    print(value)
+                    db.put_one(self.TABLE, key=key, value=value, st=now, mt=now)
+
+    def distribute(self, settings, force):
+        # for key, value in settings.items():
+        #     print(f"key: {key}, value: {value}")
+        for username in self.dest_usernames:
+            print(f"distribute settings to user '{username}'")
+            self.distribute_to_user(username, settings, force)
+
+
+class Records(TimeTaggerDB):
+    """Merge multiple ItemDB records tables"""
+
+    TABLE = "records"
+    TMP_TABLE = "records_new"
+    # INDICES = ("!key", "st", "t1", "t2")
+    # add user column. Not used by timetagger, but simply ignored.
+    INDICES = ("!key", "st", "t1", "t2", "user")
+
+    def __init__(self, target_username=None):
+        self.logger = logging.getLogger()
+        self.target_username = target_username
+        if self.target_username:
+            self.target_db_filename = user2filename(target_username)
+            self.target_db = ItemDB(self.target_db_filename)
+            self.target_db.ensure_table(self.TMP_TABLE, *self.INDICES)
+
+    def dump_db_by_usernames(self, users):
+        if not users:
+            users = list(self.get_timetagger_usernames())
+        super().dump_db_by_usernames(users, self.TABLE)
+
+    def clear(self):
+        with self.target_db:
+            self.target_db.delete_table(self.TABLE)
+            self.target_db.ensure_table(self.TABLE, *self.INDICES)
+
+    def merge_user_db(self, username, replace_dict):
+        if self.target_username is None:
+            raise RuntimeError("Target database is not initialized")
+        filename = user2filename(username)
+        db = ItemDB(filename)
+        if not itemdb_exists(db, self.TABLE):
+            raise RuntimeError(
+                f"Accessing database {filename} failed: no such file or table ({self.TABLE})"
+            )
+        with self.target_db:
+            with db:
+                for row in db.select_all(self.TABLE):
+                    try:
+                        if "#user/" not in row["ds"]:
+                            row["ds"] += f" #user/{username}"
+                    except KeyError:
+                        row["ds"] = f"#user/{username}"
+                    row["user"] = username
+                    if replace_dict:
+                        for orig, replacement in replace_dict.items():
+                            row["ds"] = row["ds"].replace(orig, replacement)
+                    self.target_db.put(self.TMP_TABLE, row)
+
+    def merge(self, users=None, replace=None):
+        if not users:
+            users = list(self.get_timetagger_usernames([self.target_username]))
+        replace_dict = get_translation_table(replace)
+        if replace_dict:
+            print("replacements: {}".format(pformat(replace_dict)))
+        for username in users:
+            print(f"merging user records of '{username}'")
+            self.merge_user_db(username, replace_dict)
+        with self.target_db:
+            # delete running timers
+            self.target_db.delete(self.TMP_TABLE, "t1 = t2")
+        with self.target_db:
+            if itemdb_exists(self.target_db, self.TABLE):
+                self.target_db.delete_table(self.TABLE)
+            self.target_db.rename_table(self.TMP_TABLE, self.TABLE)
+
+
+def handle_users_command(args):
+    # currently, there is only the list subcommand:
+    print(list(TimeTaggerDB().get_timetagger_usernames()))
+
+
+def handle_settings_command(args):
+    settings = Settings(args.dest)
+    if args.source:
+        settings_data = json.load(args.source)
+        # pprint(settings_data)
+        settings.distribute(settings_data, args.force)
+    elif args.dump:
+        settings.dump()
+    else:
+        args.parser.print_help()
+
+
+def handle_records_command(args):
+    if args.dump:
+        Records().dump_db_by_usernames(args.source_user)
+        sys.exit(0)
+    elif args.merge:
+        print(f"creating database for user '{args.dest}'")
+        print(f"filename: {user2filename(args.dest)}")
+        records = Records(args.dest)
+        records.merge(args.source_user, args.replace)
+    else:
+        args.parser.print_help()
+
+
+if __name__ == "__main__":
+    logging.basicConfig(
+        format="%(levelname)s %(module)s.%(funcName)s: %(message)s", level=logging.INFO
+    )
+    logger = logging.getLogger()
+
+    parser = setup_parser()
+    args = parser.parse_args()
+    if args.debug:
+        logger.setLevel(logging.DEBUG)
+        logger.debug(args)
+
+    if hasattr(args, "func"):
+        args.func(args)
+    else:
+        parser.print_help()
diff --git a/setup.py b/setup.py
index 7244351a..676714f9 100644
--- a/setup.py
+++ b/setup.py
@@ -33,6 +33,7 @@
     package_data={
         f"timetagger.{x}": ["*"] for x in ["common", "images", "app", "pages"]
     },
+    scripts=["contrib/multiuser_tweaks/timetagger_multiuser_tweaks.py"],
     python_requires=">=3.6.0",
     install_requires=runtime_deps,
     license="GPL-3.0",