String formatting produces incorrect result with left-aligned zero-padded format

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-12-20.14:41:00.113>
labels = ['interpreter-core']
title = 'String formatting produces incorrect result with left-aligned zero-padded format'
updated_at = <Date 2018-12-20.21:41:18.739>
user = 'https://github.com/serhiy-storchaka'

bugs.python.org fields:

activity = <Date 2018-12-20.21:41:18.739>
actor = 'eric.smith'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2018-12-20.14:41:00.113>
creator = 'serhiy.storchaka'
dependencies = []
files = []
hgrepos = []
issue_num = 35546
keywords = []
message_count = 3.0
messages = ['332231', '332244', '332265']
nosy_count = 3.0
nosy_names = ['eric.smith', 'mrabarnett', 'serhiy.storchaka']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue35546'
versions = []