@@ -957,7 +976,11 @@ static int run_git_commit(struct repository *r,

 	if (opts->committer_date_is_author_date)
 		argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
+				 opts->ignore_date ?
+				 "" :
 				 author_date_from_env_array(&cmd.env_array));
+	if (opts->ignore_date)
+		argv_array_push(&cmd.env_array, "GIT_AUTHOR_DATE=");

 	argv_array_push(&cmd.args, "commit");

@@ -1388,7 +1411,8 @@ static int try_to_commit(struct repository *r,
 			    ident.date_begin,
 			    (int)(ident.tz_end - ident.tz_begin),
 			    ident.tz_begin);
-		res = setenv("GIT_COMMITTER_DATE", date.buf, 1);
+		res = setenv("GIT_COMMITTER_DATE",
+			     opts->ignore_date ? "" : date.buf, 1);

 		strbuf_release(&date);

 		if (res)

@@ -1454,6 +1478,16 @@ static int try_to_commit(struct repository *r,

 	reset_ident_date();

+	if (opts->ignore_date) {
+		author = ignore_author_date(author);
+		if (!author) {
+			res = -1;
+			goto out;
+		}
+		free(author_to_free);

+	}
+
 	if (commit_tree_extended(msg->buf, msg->len, &tree, parents,
 				 oid, author, opts->gpg_sign, extra)) {
 		res = error(_("failed to write commit object"));

@@ -2583,6 +2617,11 @@ static int read_populate_opts(struct replay_opts *opts)
 			opts->committer_date_is_author_date = 1;
 		}

+		if (file_exists(rebase_path_ignore_date())) {
+			opts->allow_ff = 0;
+			opts->ignore_date = 1;
+		}
+
 		if (file_exists(rebase_path_reschedule_failed_exec()))
 			opts->reschedule_failed_exec = 1;

@@ -2675,6 +2714,8 @@ int write_basic_state(struct replay_opts *opts, const char *head_name,
 		write_file(rebase_path_keep_redundant_commits(), "%s", "");
 	if (opts->committer_date_is_author_date)
 		write_file(rebase_path_cdate_is_adate(), "%s", "");
+	if (opts->ignore_date)
+		write_file(rebase_path_ignore_date(), "%s", "");
 	if (opts->reschedule_failed_exec)
 		write_file(rebase_path_reschedule_failed_exec(), "%s", "");

@@ -3597,7 +3638,11 @@ static int do_merge(struct repository *r,

 		if (opts->committer_date_is_author_date)
 			argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
+					 opts->ignore_date ?
+					 "" :
 					 author_date_from_env_array(&cmd.env_array));
+		if (opts->ignore_date)
+			argv_array_push(&cmd.env_array, "GIT_AUTHOR_DATE=");

 		cmd.git_cmd = 1;
 		argv_array_push(&cmd.args, "merge");

@@ -3877,7 +3922,8 @@ static int pick_commits(struct repository *r,
 	if (opts->allow_ff)
 		assert(!(opts->signoff || opts->no_commit ||
 				opts->record_origin || opts->edit ||
-				opts->committer_date_is_author_date));
+				opts->committer_date_is_author_date ||
+				opts->ignore_date));
 	if (read_and_refresh_cache(r, opts))
 		return -1;

diff --git a/sequencer.h b/sequencer.h
index 4ab94119ae..3587878e3b 100644
--- a/sequencer.h
+++ b/sequencer.h

@@ -46,6 +46,7 @@ struct replay_opts {
 	int quiet;
 	int reschedule_failed_exec;
 	int committer_date_is_author_date;
+	int ignore_date;

 	int mainline;

diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
index 50a63d8ebe..0ede2b8900 100755
--- a/t/t3436-rebase-more-options.sh
+++ b/t/t3436-rebase-more-options.sh

@@ -108,6 +108,62 @@ test_expect_success '--committer-date-is-author-date works when committing confl
 	test_ctime_is_atime -1
 '

+# Checking for +0000 in the author date is sufficient since the
+# default timezone is UTC but the timezone used while committing is
+# +0530. The inverted logic in the grep is necessary to check all the
+# author dates in the file.
+test_ctime_is_ignored () {
+	git log $1 --format=%ai >authortime &&
+	! grep -v +0000 authortime
+}
+
+test_expect_success '--ignore-date works with apply backend' '
+	git commit --amend --date="$GIT_AUTHOR_DATE" &&
+	git rebase --apply --ignore-date HEAD^ &&
+	test_ctime_is_ignored -1
+'
+
+test_expect_success '--ignore-date works with merge backend' '
+	git commit --amend --date="$GIT_AUTHOR_DATE" &&
+	git rebase --ignore-date -m HEAD^ &&
+	test_ctime_is_ignored -1
+'
+
+test_expect_success '--ignore-date works after conflict resolution' '
+	test_must_fail git rebase --ignore-date -m \
+		--onto commit2^^ commit2^ commit2 &&
+	echo resolved >foo &&
+	git add foo &&
+	git rebase --continue &&
+	test_ctime_is_ignored -1
+'
+
+test_expect_success '--ignore-date works with rebase -r' '
+	git checkout side &&
+	git merge --no-ff commit3 &&
+	git rebase -r --root --ignore-date &&
+	test_ctime_is_ignored
+'
+
+test_expect_success '--ignore-date with --committer-date-is-author-date works' '
+	test_must_fail git rebase -m --committer-date-is-author-date \
+		--ignore-date --onto commit2^^ commit2^ commit3 &&
+	git checkout --theirs foo &&
+	git add foo &&
+	git rebase --continue &&
+	test_ctime_is_atime -2 &&
+	test_ctime_is_ignored -2
+'
+
+test_expect_success '--ignore-date --committer-date-is-author-date works when forking merge' '
+	GIT_SEQUENCE_EDITOR="echo \"merge -C $(git rev-parse HEAD) commit3\">" \
+		PATH="./test-bin:$PATH" git rebase -i --strategy=test \
+				--ignore-date --committer-date-is-author-date \
+				side side &&
+	test_ctime_is_atime -1 &&
+	test_ctime_is_ignored -1
+ '
+
 # This must be the last test in this file
 test_expect_success '$EDITOR and friends are unchanged' '
 	test_editor_unchanged
--

2.27.0