This is a would-be plural string used in the media manager. If there is not a word you can use in your language to avoid issues with the lack of plural support here, turn it into “selected: %d” then translate it.

Localized date format, see https://www.php.net/manual/datetime.format.php
Date format, see https://www.php.net/manual/datetime.format.php
1: Name of most recent post author, 2: Post edited date, 3: Post edited time.
1: Post edited date, 2: Post edited time.
1: Post creation date, 2: Post creation time.
Default date format, see https://www.php.net/manual/datetime.format.php
1: Date, 2: Time.

Localized time format, see https://www.php.net/manual/datetime.format.php
Time format, see https://www.php.net/manual/datetime.format.php
Comment time format. See https://www.php.net/manual/datetime.format.php
1: Name of most recent post author, 2: Post edited date, 3: Post edited time.
1: Post edited date, 2: Post edited time.
1: Post creation date, 2: Post creation time.
Post time format. See https://www.php.net/manual/datetime.format.php
Default time format, see https://www.php.net/manual/datetime.format.php

Localized date and time format, see https://www.php.net/manual/datetime.format.php
Date/Time format, see https://www.php.net/manual/datetime.format.php
Links last updated date format, see https://www.php.net/manual/datetime.format.php