diff --git a/builtin/reflog.c b/builtin/reflog.c
index b3c9e27bde..44700f9243 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -496,11 +496,9 @@ static int parse_expire_cfg_value(const char *var, const char *value, unsigned l
 {
 	if (!value)
 		return config_error_nonbool(var);
-	if (!strcmp(value, "never") || !strcmp(value, "false")) {
-		*expire = 0;
-		return 0;
-	}
-	*expire = approxidate(value);
+	if (parse_expiry_date(value, expire))
+		return error(_("%s' for '%s' is not a valid timestamp"),
+			     value, var);
 	return 0;
 }
 
@@ -613,11 +611,13 @@ static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 		if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
 			cb.dry_run = 1;
 		else if (!prefixcmp(arg, "--expire=")) {
-			cb.expire_total = approxidate(arg + 9);
+			if (parse_expiry_date(arg + 9, &cb.expire_total))
+				die(_("'%s' is not a valid timestamp"), arg);
 			explicit_expiry |= EXPIRE_TOTAL;
 		}
 		else if (!prefixcmp(arg, "--expire-unreachable=")) {
-			cb.expire_unreachable = approxidate(arg + 21);
+			if (parse_expiry_date(arg + 21, &cb.expire_unreachable))
+				die(_("'%s' is not a valid timestamp"), arg);
 			explicit_expiry |= EXPIRE_UNREACH;
 		}
 		else if (!strcmp(arg, "--stale-fix"))
diff --git a/cache.h b/cache.h
index 3622e18415..f43f6d94e3 100644
--- a/cache.h
+++ b/cache.h
@@ -878,6 +878,7 @@ void show_date_relative(unsigned long time, int tz, const struct timeval *now,
 			struct strbuf *timebuf);
 int parse_date(const char *date, char *buf, int bufsize);
 int parse_date_basic(const char *date, unsigned long *timestamp, int *offset);
+int parse_expiry_date(const char *date, unsigned long *timestamp);
 void datestamp(char *buf, int bufsize);
 #define approxidate(s) approxidate_careful((s), NULL)
 unsigned long approxidate_careful(const char *, int *);
diff --git a/date.c b/date.c
index 57331ed406..876d679b1e 100644
--- a/date.c
+++ b/date.c
@@ -705,6 +705,28 @@ int parse_date_basic(const char *date, unsigned long *timestamp, int *offset)
 	return 0; /* success */
 }
 
+int parse_expiry_date(const char *date, unsigned long *timestamp)
+{
+	int errors = 0;
+
+	if (!strcmp(date, "never") || !strcmp(date, "false"))
+		*timestamp = 0;
+	else if (!strcmp(date, "all") || !strcmp(date, "now"))
+		/*
+		 * We take over "now" here, which usually translates
+		 * to the current timestamp.  This is because the user
+		 * really means to expire everything she has done in
+		 * the past, and by definition reflogs are the record
+		 * of the past, and there is nothing from the future
+		 * to be kept.
+		 */
+		*timestamp = ULONG_MAX;
+	else
+		*timestamp = approxidate_careful(date, &errors);
+
+	return errors;
+}
+
 int parse_date(const char *date, char *result, int maxlen)
 {
 	unsigned long timestamp;