Info Catalog coreutils: Literal conversion specifiers coreutils: date invocation coreutils: Setting the time

coreutils: Padding and other flags

 
 21.1.4 Padding and other flags
 ------------------------------
 
 Unless otherwise specified, ‘date’ normally pads numeric fields with
 zeros, so that, for example, numeric months are always output as two
 digits.  Seconds since the epoch are not padded, though, since there is
 no natural width for them.
 
    The following optional flags can appear after the ‘%’:
 
 ‘-’
      (hyphen) Do not pad the field; useful if the output is intended for
      human consumption.  This is a GNU extension.
 ‘_’
      (underscore) Pad with spaces; useful if you need a fixed number of
      characters in the output, but zeros are too distracting.  This is a
      GNU extension.
 ‘0’
      (zero) Pad with zeros even if the conversion specifier would
      normally pad with spaces.
 ‘+’
      Pad with zeros, like ‘0’.  In addition, precede any year number
      with ‘+’ if it exceeds 9999 or if its field width exceeds 4;
      similarly, precede any century number with ‘+’ if it exceeds 99 or
      if its field width exceeds 2.  This supports ISO 8601 formats for
      dates far in the future; for example, the command ‘date
      --date=12019-02-25 +%+13F’ outputs the string ‘+012019-02-25’.
 ‘^’
      Use upper case characters if possible.  This is a GNU extension.
 ‘#’
      Use opposite case characters if possible.  A field that is normally
      upper case becomes lower case, and vice versa.  This is a GNU
      extension.
 
 Here are some examples of padding:
 
      date +%d/%m -d "Feb 1"
      ⇒ 01/02
      date +%-d/%-m -d "Feb 1"
      ⇒ 1/2
      date +%_d/%_m -d "Feb 1"
      ⇒  1/ 2
 
    You can optionally specify the field width (after any flag, if
 present) as a decimal number.  If the natural size of the output of the
 field has less than the specified number of characters, the result is
 written right adjusted and padded to the given size.  For example, ‘%9B’
 prints the right adjusted month name in a field of width 9.
 
    An optional modifier can follow the optional flag and width
 specification.  The modifiers are:
 
 ‘E’
      Use the locale’s alternate representation for date and time.  This
      modifier applies to the ‘%c’, ‘%C’, ‘%x’, ‘%X’, ‘%y’ and ‘%Y’
      conversion specifiers.  In a Japanese locale, for example, ‘%Ex’
      might yield a date format based on the Japanese Emperors’ reigns.
 
 ‘O’
      Use the locale’s alternate numeric symbols for numbers.  This
      modifier applies only to numeric conversion specifiers.
 
    If the format supports the modifier but no alternate representation
 is available, it is ignored.
 
    POSIX specifies the behavior of flags and field widths only for ‘%C’,
 ‘%F’, ‘%G’, and ‘%Y’ (all without modifiers), and requires a flag to be
 present if and only if a field width is also present.  Other
 combinations of flags, field widths and modifiers are GNU extensions.
 

Info Catalog coreutils: Literal conversion specifiers coreutils: date invocation coreutils: Setting the time