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.
 
    As a GNU extension, ‘date’ recognizes any of the following optional
 flags after the ‘%’:
 
 ‘-’
      (hyphen) Do not pad the field; useful if the output is intended for
      human consumption.
 ‘_’
      (underscore) Pad with spaces; useful if you need a fixed number of
      characters in the output, but zeros are too distracting.
 ‘0’
      (zero) Pad with zeros even if the conversion specifier would
      normally pad with spaces.
 ‘^’
      Use upper case characters if possible.
 ‘#’
      Use opposite case characters if possible.  A field that is normally
      upper case becomes lower case, and vice versa.
 
 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
 
    As a GNU extension, you can 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.
 

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