Redmi3, MIUI 8.2.1, Russian Language.
Downloaded ido_xhdpi_images_8.2.1_20180201.0000.00_5.1_cn_98d739cd99.tgz
Then, using MyFlash, downloaded this firmware to the phone, the mode "clear all". After that, turned on the phone, made the initial settings. After that, using the TWRP, installed xiaomi.eu_multi_HM3_8.2.1_v9-5.1.zip
Has added an account of Google. Contacts from the account are downloaded to the phone book. Information about birthdays in the phone book is also there.
However,...
Calendar - Don't Load Contact Birthday Info From A Google Account
Downloaded ido_xhdpi_images_8.2.1_20180201.0000.00_5.1_cn_98d739cd99.tgz
Then, using MyFlash, downloaded this firmware to the phone, the mode "clear all". After that, turned on the phone, made the initial settings. After that, using the TWRP, installed xiaomi.eu_multi_HM3_8.2.1_v9-5.1.zip
Has added an account of Google. Contacts from the account are downloaded to the phone book. Information about birthdays in the phone book is also there.
However,...
Calendar - Don't Load Contact Birthday Info From A Google Account