code: def strftime(format, time, zone_id):
      """
      Convert Unix timestamp to a formatted datetime string.
  
      Examples
      --------
  
      >>> hl.eval(hl.experimental.strftime("%Y.%m.%d %H:%M:%S %z", 1562569201, "America/New_York"))
      '2019.07.08 03:00:01 -04:00'
  
      >>> hl.eval(hl.experimental.strftime("%A, %B %e, %Y. %r", 876541523, "GMT+2"))
      'Saturday, October 11, 1997. 05:45:23 AM'
  
      >>> hl.eval(hl.experimental.strftime("%A, %B %e, %Y. %r", 876541523, "+08:00"))
      'Saturday, October 11, 1997. 11:45:23 AM'
  
  
      Notes
      -----
      The following formatting characters are supported in format strings: A a B b D d e F H I j k l M m n p R r S s T t U u V v W Y y z
      See documentation here: https://linux.die.net/man/3/strftime
  
      A zone id can take one of three forms. It can be an explicit offset, like "+01:00", a relative offset, like "GMT+2",
      or a IANA timezone database (TZDB) identifier, like "America/New_York". Wikipedia maintains a list of TZDB identifiers here: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
  
      Currently, the formatter implicitly uses the "en_US" locale.
  
      Parameters
      ----------
      format : str or :class:`.Expression` of type :py:data:`.tstr`
          The format string describing how to render the time.
      time : int of :class:`.Expression` of type :py:data:`.tint64`
          A long representing the time as a Unix timestamp.
      zone_id: str or :class:`.Expression` of type :py:data:`.tstr`
          An id representing the timezone. See notes above.
  
      Returns
      -------
      :class:`~.StringExpression`
          A string of the specified format based on the requested time.
      """
      return _func("strftime", hl.tstr, format, time, zone_id)
  
imports: import hail
  from hail.expr.expressions import expr_str, expr_int64
  from hail.expr.functions import _func
  from hail.typecheck import typecheck
label_desc: Use image node_id 1 for calling a global function with example usage: strftime(format, time, zone_id) and returns: _func