Strange this may happen in this world, one day you wake up and see Google been shutdown along with its valuable other products (only imagine it please), then you will loose a part of your life. No worries Google is not going anywhere, they have added ability to export a complete copy of your Gmail and Google Calendar data.
As per the latest announcement from Google, customers will be able to download their Gmail and Google calender data from Google servers to keep a personal backup of your data or shift out to another service. Customer will have a choice to download all their mail and calender data or can specifically download a subset of labels and calendars. They can also couple the backup with other Google products like Google+, YouTube, Drive and other Google data that support downloading backup into a single archive file.
Google download backup Service (earlier called Takeout service) lets users take their data out of multiple Google products in one single archive which are portable and in open formats‚ so it can be easily imported to other services quickly.