Module: Jekyll::Utils::WinTZ

Extended by:
WinTZ
Included in:
WinTZ
Defined in:
lib/jekyll/utils/win_tz.rb

Instance Method Summary collapse

Instance Method Details

#calculate(timezone, now = Time.now) ⇒ Object

Public: Calculate the Timezone for Windows when the config file has a defined

'timezone' key.

timezone - the IANA Time Zone specified in “_config.yml”

Returns a string that ultimately re-defines ENV in Windows



14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
# File 'lib/jekyll/utils/win_tz.rb', line 14

def calculate(timezone, now = Time.now)
  External.require_with_graceful_fail("tzinfo") unless defined?(TZInfo)
  tz = TZInfo::Timezone.get(timezone)

  #
  # Use period_for_utc and utc_total_offset instead of
  # period_for and observed_utc_offset for compatibility with tzinfo v1.
  offset = tz.period_for_utc(now.getutc).utc_total_offset

  #
  # POSIX style definition reverses the offset sign.
  #   e.g. Eastern Standard Time (EST) that is 5Hrs. to the 'west' of Prime Meridian
  #   is denoted as:
  #     EST+5 (or) EST+05:00
  # Reference: https://www.gnu.org/software/libc/manual/html_node/TZ-Variable.html
  sign = offset.positive? ? "-" : "+"

  rational_hours = offset.abs.to_r / 3600
  hours = rational_hours.to_i
  minutes = ((rational_hours - hours) * 60).to_i

  #
  # Format the hours and minutes as two-digit numbers.
  time = format("%<hours>02d:%<minutes>02d", :hours => hours, :minutes => minutes)

  Jekyll.logger.debug "Timezone:", "#{timezone} #{sign}#{time}"
  #
  # Note: The 3-letter-word below doesn't have a particular significance.
  "WTZ#{sign}#{time}"
end