diff --git a/python/pyiceberg/utils/datetime.py b/python/pyiceberg/utils/datetime.py
index 3d23f38b3016..1ab56d6ea335 100644
--- a/python/pyiceberg/utils/datetime.py
+++ b/python/pyiceberg/utils/datetime.py
@@ -27,9 +27,9 @@
 
 EPOCH_DATE = date.fromisoformat("1970-01-01")
 EPOCH_TIMESTAMP = datetime.fromisoformat("1970-01-01T00:00:00.000000")
-ISO_TIMESTAMP = re.compile(r"\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\d(.\d{1,6})?")
+ISO_TIMESTAMP = re.compile(r"\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(.\d{1,6})?")
 EPOCH_TIMESTAMPTZ = datetime.fromisoformat("1970-01-01T00:00:00.000000+00:00")
-ISO_TIMESTAMPTZ = re.compile(r"\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\d(.\d{1,6})?[-+]\d\d:\d\d")
+ISO_TIMESTAMPTZ = re.compile(r"\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(.\d{1,6})?[-+]\d{2}:\d{2}")
 
 
 def micros_to_days(timestamp: int) -> int: