Google announced on Friday that it will shut down several "less popular" products, features and services as part of a "winter cleaning" effort.

Google Calendar will see several losses on Jan. 4, after which users will be unable to create new reservable times through appointment slots, though existing appointment slots in Google Calendar will continue working for a year after that date.

In addition, the Calendar Labs "Smart Rescheduler" and "Add gadget by URL" will be discontinued that same day.

Finally, as of today, U.S. users' ability to check their Google Calendars and create events via SMS will be eliminated, since, according to Google, most people just use Calendar apps at this point.

Goodbye to Google Sync

Google Sync, which provided users access to Gmail, Google Calendar and Contacts via the Microsoft Exchange ActiveSync protocol, will be discontinued as well on Jan. 30.

According to Google Vice President of Engineering Venkat Panchapakesan, who wrote the Google blog post describing the upcoming changes, Google currently offers users access to the same data via other protocols, making Google Sync obsolete.

Existing connections will continue to work, but users will not be able to set up new Google Sync connections.

Google Sync will also continue to be supported for Google Apps for Business, Government and Education.

That's not all, folks

As of Friday, Google Calendar Sync will no longer function either, with Google Sync for the Nokia S60 and SyncML, a contacts sync service for older devices, stopping on Jan. 30 as well.

Finally, Google's Issue Tracker Data API, which let client applications view and update issues with Google Data API feeds, will stop working on June 14 next year, and Punchd, a digital loyalty card app on iOS and Android, will be discontinued on June 7.

Punchd merchants will no longer have to honor Punchd loyalty cards, though Google remains "focused on developing products that help merchants and shoppers connect in new and useful ways," Panchapakesan wrote on Friday.

"Last January, we renewed our resolution to focus on creating beautiful, useful products that improve millions of people's lives every day," he added. "To make the most impact, we need to make some difficult decisions."

"Technology offers us a way to make a big impact on the world," Panchapakesan concluded. "In 2013, we'll keep working hard to build a seamless, amazing Google experience for you."