From 5172a8894e5fd470bbf441111412f2cf0b9da064 Mon Sep 17 00:00:00 2001
From: Kadir Can Ozden <101993364+bysiber@users.noreply.github.com>
Date: Fri, 20 Feb 2026 08:27:52 +0300
Subject: [PATCH] Fix _TIMESTAMP_RE to match single-digit timestamps

The regex \d+\.?\d+ requires at least one digit on each side of
the optional decimal point. For single-digit values like "0" or
"1", the first \d+ consumes the only digit and the second \d+
fails to match anything.

Change the trailing \d+ to \d* so the decimal part is fully
optional, allowing single-digit timestamps like epoch 0 to be
parsed with the X format token.
---
 arrow/parser.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arrow/parser.py b/arrow/parser.py
index fc3774b0..96f0404c 100644
--- a/arrow/parser.py
+++ b/arrow/parser.py
@@ -166,7 +166,7 @@ class DateTimeParser:
     _TZ_NAME_RE: ClassVar[Pattern[str]] = re.compile(r"\w[\w+\-/]+")
     # NOTE: timestamps cannot be parsed from natural language strings (by removing the ^...$) because it will
     # break cases like "15 Jul 2000" and a format list (see issue #447)
-    _TIMESTAMP_RE: ClassVar[Pattern[str]] = re.compile(r"^\-?\d+\.?\d+$")
+    _TIMESTAMP_RE: ClassVar[Pattern[str]] = re.compile(r"^\-?\d+\.?\d*$")
     _TIMESTAMP_EXPANDED_RE: ClassVar[Pattern[str]] = re.compile(r"^\-?\d+$")
     _TIME_RE: ClassVar[Pattern[str]] = re.compile(
         r"^(\d{2})(?:\:?(\d{2}))?(?:\:?(\d{2}))?(?:([\.\,])(\d+))?$"