Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_88 (date VARCHAR, city VARCHAR, type_of_game VARCHAR)
### Question:
When did Yugoslavia play a friendly game in Belgrade?
### Answer:
SELECT date FROM table_name_88 WHERE city = "belgrade" AND type_of_game = "friendly"