Substitute various time-related information for each %-code in the string, as per formatCharacter .

The general form is %<modifier><width><alternate><specifier> , where <modifier> , <width> , and <alternate> are optional.

<modifier>

glibc-style modifiers can be used before the specifier (here marked as z ):

%-z

no padding

%_z

pad with spaces

%0z

pad with zeros

%^z

convert to upper case

%#z

convert to lower case (consistently, unlike glibc)

<width>

Width digits can also be used after any modifiers and before the specifier (here marked as z ), for example:

%4z

pad to 4 characters (with default padding character)

%_12z

pad with spaces to 12 characters

<alternate>

An optional E character indicates an alternate formatting. Currently this only affects %Z and %z .

%Ez

alternate formatting

<specifier>

For all types (note these three are done by formatTime , not by formatCharacter ):

%%

%

%t

tab

%n

newline

TimeZone

For TimeZone (and ZonedTime and UTCTime ):

%z

timezone offset in the format ±HHMM

%Ez

timezone offset in the format ±HH:MM

%Z

timezone name (or else offset in the format ±HHMM )

%EZ

timezone name (or else offset in the format ±HH:MM )

LocalTime

For LocalTime (and ZonedTime and UTCTime and UniversalTime ):

%c

as dateTimeFmt locale (e.g. %a %b %e %H:%M:%S %Z %Y )

TimeOfDay

For TimeOfDay (and LocalTime and ZonedTime and UTCTime and UniversalTime ):

%R

same as %H:%M

%T

same as %H:%M:%S

%X

as timeFmt locale (e.g. %H:%M:%S )

%r

as time12Fmt locale (e.g. %I:%M:%S %p )

%P

day-half of day from ( amPm locale ), converted to lowercase, am , pm

%p

day-half of day from ( amPm locale ), AM , PM

%H

hour of day (24-hour), 0-padded to two chars, 00 - 23

%k

hour of day (24-hour), space-padded to two chars, 0 - 23

%I

hour of day-half (12-hour), 0-padded to two chars, 01 - 12

%l

hour of day-half (12-hour), space-padded to two chars, 1 - 12

%M

minute of hour, 0-padded to two chars, 00 - 59

%S

second of minute (without decimal part), 0-padded to two chars, 00 - 60

%q

picosecond of second, 0-padded to twelve chars, 000000000000 - 999999999999 .

%Q

decimal point and fraction of second, up to 12 second decimals, without trailing zeros. For a whole number of seconds, %Q omits the decimal point unless padding is specified.

UTCTime and ZonedTime

For UTCTime and ZonedTime :

%s

number of whole seconds since the Unix epoch. For times before the Unix epoch, this is a negative number. Note that in %s.%q and %s%Q the decimals are positive, not negative. For example, 0.9 seconds before the Unix epoch is formatted as -1.1 with %s%Q .

DayOfWeek

For DayOfWeek (and Day and LocalTime and ZonedTime and UTCTime and UniversalTime ):

%u

day of week number for Week Date format, 1 (= Monday) - 7 (= Sunday)

%w

day of week number, 0 (= Sunday) - 6 (= Saturday)

%a

day of week, short form ( snd from wDays locale ), Sun - Sat

%A

day of week, long form ( fst from wDays locale ), Sunday - Saturday

Day

For Day (and LocalTime and ZonedTime and UTCTime and UniversalTime ):

%D

same as %m/%d/%y

%F

same as %Y-%m-%d

%x

as dateFmt locale (e.g. %m/%d/%y )

%Y

year, no padding. Note %0Y and %_Y pad to four chars

%y

year of century, 0-padded to two chars, 00 - 99

%C

century, no padding. Note %0C and %_C pad to two chars

%B

month name, long form ( fst from months locale ), January - December

%b , %h

month name, short form ( snd from months locale ), Jan - Dec

%m

month of year, 0-padded to two chars, 01 - 12

%d

day of month, 0-padded to two chars, 01 - 31

%e

day of month, space-padded to two chars, 1 - 31

%j

day of year, 0-padded to three chars, 001 - 366

%f

century for Week Date format, no padding. Note %0f and %_f pad to two chars

%V

week of year for Week Date format, 0-padded to two chars, 01 - 53

%U

week of year where weeks start on Sunday (as sundayStartWeek ), 0-padded to two chars, 00 - 53

%W

week of year where weeks start on Monday (as mondayStartWeek ), 0-padded to two chars, 00 - 53

Duration types

The specifiers for DiffTime , NominalDiffTime , CalendarDiffDays , and CalendarDiffTime are semantically separate from the other types. Specifiers on negative time differences will generally be negative (think rem rather than mod ).

NominalDiffTime and DiffTime

Note that a "minute" of DiffTime is simply 60 SI seconds, rather than a minute of civil time. Use NominalDiffTime to work with civil time, ignoring any leap seconds.

For NominalDiffTime and DiffTime :

%w

total whole weeks

%d

total whole days

%D

whole days of week

%h

total whole hours

%H

whole hours of day

%m

total whole minutes

%M

whole minutes of hour

%s

total whole seconds

%Es

total seconds, with decimal point and up to <width> (default 12) decimal places, without trailing zeros. For a whole number of seconds, %Es omits the decimal point unless padding is specified.

%0Es

total seconds, with decimal point and <width> (default 12) decimal places.

%S

whole seconds of minute

%ES

seconds of minute, with decimal point and up to <width> (default 12) decimal places, without trailing zeros. For a whole number of seconds, %ES omits the decimal point unless padding is specified.

%0ES

seconds of minute as two digits, with decimal point and <width> (default 12) decimal places.

CalendarDiffDays

For CalendarDiffDays (and CalendarDiffTime ):

%y

total years

%b

total months

%B

months of year

%w

total weeks, not including months

%d

total days, not including months

%D

days of week

CalendarDiffTime

For CalendarDiffTime :

%h

total hours, not including months

%H

hours of day

%m

total minutes, not including months

%M

minutes of hour

%s

total whole seconds, not including months

%Es

total seconds, not including months, with decimal point and up to <width> (default 12) decimal places, without trailing zeros. For a whole number of seconds, %Es omits the decimal point unless padding is specified.

%0Es

total seconds, not including months, with decimal point and <width> (default 12) decimal places.

%S

whole seconds of minute

%ES

seconds of minute, with decimal point and up to <width> (default 12) decimal places, without trailing zeros. For a whole number of seconds, %ES omits the decimal point unless padding is specified.

%0ES

seconds of minute as two digits, with decimal point and <width> (default 12) decimal places.

Parses a time value given a format string. Supports the same %-codes as formatTime , including %- , %_ and %0 modifiers, however padding widths are not supported. Case is not significant in the input string. Some variations in the input are accepted:

%z

accepts any of ±HHMM or ±HH:MM .

%Z

accepts any string of letters, or any of the formats accepted by %z .

%0Y

accepts exactly four digits.

%0G

accepts exactly four digits.

%0C

accepts exactly two digits.

%0f

accepts exactly two digits.

For example, to parse a date in YYYY-MM-DD format, while allowing the month and date to have optional leading zeros (notice the - modifier used for %m and %d ):

Prelude Data.Time> parseTimeM True defaultTimeLocale "%Y-%-m-%-d" "2010-3-04" :: Maybe Day
Just 2010-03-04

Parse a time value given a format string. Fails if the input could not be parsed using the given format. See parseTimeM for details.

Parse a time value given a format string. See parseTimeM for details.

Parse a time value given a format string. See parseTimeM for details.

The class of types which can be parsed given a UNIX-style time format string.

Locale representing American usage.

knownTimeZones contains only the ten time-zones mentioned in RFC 822 sec. 5: "UT", "GMT", "EST", "EDT", "CST", "CDT", "MST", "MDT", "PST", "PDT". Note that the parsing functions will regardless parse "UTC", single-letter military time-zones, and +HHMM format.

Construct format string according to ISO-8601 .

The Maybe String argument allows to supply an optional time specification. E.g.:

iso8601DateFormat Nothing            == "%Y-%m-%d"           -- i.e. YYYY-MM-DD
iso8601DateFormat (Just "%H:%M:%S")  == "%Y-%m-%dT%H:%M:%S"  -- i.e. YYYY-MM-DDTHH:MM:SS

Format string according to RFC822 .