google-api-ruby-client设置日历事件起止时间时区异常问题

I’ve run into this exact issue before—it’s all about how your time objects are being parsed and passed to the API. Let’s break down what’s happening and how to fix it:

What’s Going Wrong #

Your code uses DateTime.parse(date_string) which creates a time object in your local timezone (looks like Pacific Time, -0700) instead of the Europe/London timezone you specified. When you pass this local-time DateTime to the API alongside time_zone: "Europe/London", Google’s API gets confused: it takes the -0700 offset time, converts it to UTC, then shifts it again to Europe/London time—resulting in that incorrect early-morning time you’re seeing.

The Fix: Ensure Your Time Objects Are in the Target Timezone #

You need to explicitly parse or convert your time to the Europe/London timezone before sending it to the API. Here are two common approaches depending on whether you’re using Rails or plain Ruby:

Option 1: If You’re Using Rails (ActiveSupport)

Rails makes timezone handling straightforward. Use ActiveSupport::TimeZone to parse the time directly into your target timezone:

def service
  secrets = setup_credentials
  service = Google::Apis::CalendarV3::CalendarService.new
  service.client_options.application_name = 'Quickstart'
  service.authorization = secrets.to_authorization
  event_id = "yyyzzzzzzxxxxx"

  # Parse the time directly in Europe/London timezone
  target_tz = ActiveSupport::TimeZone.new("Europe/London")
  date = target_tz.parse("2018-4-23 10:45AM")
  end_date = date + 1.hour

  event = { 
    summary: "hype event", 
    start: {date_time: date, time_zone: "Europe/London"}, 
    end: {date_time: end_date, time_zone: "Europe/London"} 
  }
  service.update_event('primary', event_id, event, send_notifications: true)
end

Option 2: Plain Ruby (Using tzinfo Gem)

If you’re not using Rails, add the tzinfo gem to your project (it handles timezone conversions reliably):

1. Add gem 'tzinfo' to your Gemfile and run bundle install
2. Update your code to parse the time into the correct timezone:

require 'tzinfo'

def service
  secrets = setup_credentials
  service = Google::Apis::CalendarV3::CalendarService.new
  service.client_options.application_name = 'Quickstart'
  service.authorization = secrets.to_authorization
  event_id = "yyyzzzzzzxxxxx"

  # Get the Europe/London timezone object
  london_tz = TZInfo::Timezone.get("Europe/London")
  # Parse the input string as a local time in Europe/London
  date = london_tz.strptime("2018-4-23 10:45AM", "%Y-%m-%d %I:%M%p")
  end_date = date + 3600 # Add 1 hour in seconds to avoid timezone drift

  # Pass the time as an RFC3339 string (the API loves this format)
  event = { 
    summary: "hype event", 
    start: {date_time: date.rfc3339, time_zone: "Europe/London"}, 
    end: {date_time: end_date.rfc3339, time_zone: "Europe/London"} 
  }
  service.update_event('primary', event_id, event, send_notifications: true)
end

Another Quick Hack: Use RFC3339 Strings Directly #

If you want to bypass timezone object headaches, you can construct the time as an RFC3339 string with the correct London timezone offset (remember, London uses BST in April, so +01:00):

date_string = "2018-04-23T10:45:00+01:00"
end_date_string = "2018-04-23T11:45:00+01:00"

event = { 
  summary: "hype event", 
  start: {date_time: date_string, time_zone: "Europe/London"}, 
  end: {date_time: end_date_string, time_zone: "Europe/London"} 
}

After making these changes, the API should return the correct Europe/London timezone times in the response, matching what you intended to save.

内容的提问来源于stack exchange，提问作者brg