forked from jekyll/jekyll
-
Notifications
You must be signed in to change notification settings - Fork 0
/
win_tz.rb
46 lines (39 loc) · 1.58 KB
/
win_tz.rb
1
2
3
4
5
6
7
8
9
10
11
12
13
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
44
45
46
# frozen_string_literal: true
module Jekyll
module Utils
module WinTZ
extend self
# 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["TZ"] in Windows
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: http://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
end
end
end