Python strftime and strptime Format Codes

Python strftime / strptime Format Codes

Python's datetime module uses percent-prefixed directives for both formatting (strftime) and parsing (strptime). This syntax originated from the C standard library and is also used by Ruby and other languages.

Core Directives

Directive	Meaning	Example
%Y	Year (4-digit)	2026
%y	Year (2-digit)	26
%m	Month (zero-padded)	02
%-m	Month (no padding)	2
%B	Full month name	February
%b	Abbreviated month	Feb
%d	Day (zero-padded)	28
%-d	Day (no padding)	28
%A	Full weekday	Saturday
%a	Abbreviated weekday	Sat
%H	Hour 24h (zero-padded)	14
%I	Hour 12h (zero-padded)	02
%M	Minute (zero-padded)	30
%S	Second (zero-padded)	00
%p	AM/PM	PM
%j	Day of year (zero-padded)	059
%z	UTC offset	+0900
%Z	Timezone name	JST

Formatting vs Parsing

from datetime import datetime

# Formatting (datetime → string)
dt = datetime(2026, 2, 28, 14, 30, 0)
dt.strftime("%Y-%m-%d %H:%M:%S")  # "2026-02-28 14:30:00"

# Parsing (string → datetime)
datetime.strptime("2026-02-28 14:30:00", "%Y-%m-%d %H:%M:%S")

Platform-Specific Directives

The %- prefix (e.g., %-d, %-m) removes zero-padding on Linux/macOS but is not supported on Windows. On Windows, use %#d and %#m instead.

Common Patterns

"%Y-%m-%d"                    # 2026-02-28
"%Y-%m-%d %H:%M:%S"          # 2026-02-28 14:30:00
"%B %d, %Y"                  # February 28, 2026
"%m/%d/%Y"                   # 02/28/2026
"%d/%m/%Y"                   # 28/02/2026
"%a, %d %b %Y %H:%M:%S %z"  # Sat, 28 Feb 2026 14:30:00 +0900
"%I:%M %p"                   # 02:30 PM

Python 3.6+ f-strings

f"{dt:%Y-%m-%d %H:%M}"  # "2026-02-28 14:30"