`strftime` and `strptime` format codes¶

The full table of directives, with examples for each. Both strftime (format a datetime as a string) and strptime (parse a string into a datetime) use the same set of codes.

Examples are all formatted from this datetime: datetime(2026, 4, 21, 14, 30, 5) — a Tuesday, day 112 of the year.

Year¶

Directive	Meaning	Example
`%Y`	Year, 4 digits, zero-padded	`2026`
`%y`	Year, 2 digits, zero-padded	`26`
`%G`	ISO week year (4-digit)	`2026`
`%C`	Century	`20`

Prefer %Y — %y is ambiguous for years spanning centuries.

Month¶

Directive	Meaning	Example
`%m`	Month as zero-padded number	`04`
`%B`	Full month name (English)	`April`
`%b`	Abbreviated month name	`Apr`

Day¶

Directive	Meaning	Example
`%d`	Day of month, zero-padded	`21`
`%e`	Day of month, space-padded	`21` (Linux/macOS only)
`%j`	Day of year (001–366)	`112`

Weekday¶

Directive	Meaning	Example
`%A`	Full weekday name (English)	`Tuesday`
`%a`	Abbreviated weekday name	`Tue`
`%w`	Weekday as number (Sunday=0)	`2`
`%u`	ISO weekday (Monday=1)	`2`

Week number¶

Directive	Meaning	Example
`%V`	ISO week number (01–53)	`17`
`%U`	Week of year (Sunday first)	`16`
`%W`	Week of year (Monday first)	`16`

%V with %G and %u gives the full ISO week-date (2026-W17-2). Don't combine %V with %Y — they can disagree at year boundaries.

Time of day¶

Directive	Meaning	Example
`%H`	Hour (00–23)	`14`
`%I`	Hour (01–12)	`02`
`%p`	`AM` / `PM`	`PM`
`%M`	Minute (00–59)	`30`
`%S`	Second (00–59)	`05`
`%f`	Microsecond (000000–999999)	`000000`

Time zone¶

Directive	Meaning	Example
`%z`	UTC offset `±HHMM` or `±HH:MM`	`+0100`
`%Z`	Zone name	`BST`

%z in strftime is reliable; parsing with %z in strptime depends on the exact format. %Z parsing is unreliable across platforms — prefer fromisoformat for zone-aware strings.

Locale-sensitive (avoid if possible)¶

Directive	Meaning	Example
`%c`	Locale datetime representation	`Tue Apr 21 14:30:05 2026`
`%x`	Locale date representation	`04/21/26`
`%X`	Locale time representation	`14:30:05`

Locale-sensitive formatting depends on LC_TIME, which is global state. Avoid for machine-readable output — use explicit format strings instead.

Literal characters¶

Directive	Meaning
`%%`	A literal `%`

Any other character in the format string is treated as a literal — %d/%m/%Y has / literals between the directives.

Common format strings¶

dt = datetime(2026, 4, 21, 14, 30, 5)

dt.strftime("%Y-%m-%d")                 # 2026-04-21 (ISO date)
dt.strftime("%Y-%m-%dT%H:%M:%S")        # 2026-04-21T14:30:05 (ISO datetime)
dt.strftime("%d/%m/%Y")                 # 21/04/2026 (British)
dt.strftime("%m/%d/%Y")                 # 04/21/2026 (American)
dt.strftime("%A %d %B %Y")              # Tuesday 21 April 2026
dt.strftime("%d %b %Y, %H:%M")          # 21 Apr 2026, 14:30
dt.strftime("%Y-W%V-%u")                # 2026-W17-2 (ISO week-date)
dt.strftime("%Y%m%d")                   # 20260421 (sortable, filename-safe)
dt.strftime("%Y%m%dT%H%M%S")            # 20260421T143005 (basic ISO, filename-safe)

strftime is the same in every direction — whatever you put in the format string, that's what you get back. The inverse for parsing is strptime(string, format) using the same directives.

strftime and strptime format codes¶