diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c
index 10db03991e..d0de066355 100644
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@ -2,6 +2,7 @@
 #include "../abspath.h"
 #include "../chdir-notify.h"
 #include "../config.h"
+#include "../date.h"
 #include "../dir.h"
 #include "../environment.h"
 #include "../fsck.h"
@@ -317,7 +318,7 @@ static void fill_reftable_log_record(struct reftable_log_record *log, const stru
 		tz_begin++;
 	}
 
-	log->value.update.tz_offset = sign * atoi(tz_begin);
+	log->value.update.tz_offset = tz_to_minutes(sign * atoi(tz_begin));
 }
 
 static int reftable_be_config(const char *var, const char *value,
@@ -2186,7 +2187,7 @@ static int yield_log_record(struct reftable_ref_store *refs,
 	full_committer = fmt_ident(log->value.update.name, log->value.update.email,
 				   WANT_COMMITTER_IDENT, NULL, IDENT_NO_DATE);
 	return fn(log->refname, &old_oid, &new_oid, full_committer,
-		  log->value.update.time, log->value.update.tz_offset,
+		  log->value.update.time, minutes_to_tz(log->value.update.tz_offset),
 		  log->value.update.message, cb_data);
 }
 
@@ -2690,7 +2691,7 @@ static int reftable_be_reflog_expire(struct ref_store *ref_store,
 
 		if (should_prune_fn(&old_oid, &new_oid, logs[i].value.update.email,
 				    (timestamp_t)logs[i].value.update.time,
-				    logs[i].value.update.tz_offset,
+				    minutes_to_tz(logs[i].value.update.tz_offset),
 				    logs[i].value.update.message,
 				    policy_cb_data)) {
 			dest->value_type = REFTABLE_LOG_DELETION;
diff --git a/t/helper/test-reftable.c b/t/helper/test-reftable.c
index 57758936b0..d9f2ca1d0e 100644
--- a/t/helper/test-reftable.c
+++ b/t/helper/test-reftable.c
@@ -163,7 +163,7 @@ static int dump_table(struct reftable_merged_table *mt)
 			       log.update_index);
 			break;
 		case REFTABLE_LOG_UPDATE:
-			printf("log{%s(%" PRIu64 ") %s <%s> %" PRIu64 " %04d\n",
+			printf("log{%s(%" PRIu64 ") %s <%s> %" PRIu64 " %d\n",
 			       log.refname, log.update_index,
 			       log.value.update.name ? log.value.update.name : "",
 			       log.value.update.email ? log.value.update.email : "",
diff --git a/t/t0610-reftable-basics.sh b/t/t0610-reftable-basics.sh
index 35e98b43db..2253705a19 100755
--- a/t/t0610-reftable-basics.sh
+++ b/t/t0610-reftable-basics.sh
@@ -837,6 +837,41 @@ test_expect_success 'reflog: renaming branch writes reflog entry' '
 	)
 '
 
+test_expect_success 'reflog: timezone offset is stored in minutes' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		GIT_COMMITTER_DATE="1234567890 -1200" git commit --allow-empty -m min &&
+		GIT_COMMITTER_DATE="1234567890 +0530" git commit --allow-empty -m east &&
+		GIT_COMMITTER_DATE="1234567890 -0830" git commit --allow-empty -m west &&
+		GIT_COMMITTER_DATE="1234567890 +1400" git commit --allow-empty -m max &&
+
+		# The reftable format specifies the timezone as the offset from
+		# UTC in minutes, whereas Git uses the parsed form of "+HHMM"
+		# internally. Verify that we do the conversion when writing.
+		for table in .git/reftable/*.ref
+		do
+			test-tool dump-reftable -t "$table" || return 1
+		done >dump &&
+		sed -n "s/^log{refs\/heads\/main([0-9]*) .* 1234567890 //p" dump >actual &&
+		cat >expect <<-\EOF &&
+		840
+		-510
+		330
+		-720
+		EOF
+		test_cmp expect actual &&
+
+		# And verify that we convert back when reading.
+		test-tool ref-store main for-each-reflog-ent refs/heads/main >entries &&
+		test_grep "1234567890 -1200	commit (initial): min" entries &&
+		test_grep "1234567890 +0530	commit: east" entries &&
+		test_grep "1234567890 -0830	commit: west" entries &&
+		test_grep "1234567890 +1400	commit: max" entries
+	)
+'
+
 test_expect_success 'reflog: can store empty logs' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&