Xīngqísì
ㄒㄧㄥ ㄑㄧˊ ㄙˋ
Taivo → Settings → Partner inbox → Make the link. It stays in this browser.
昨天是星期四。
zuótiān shì Xīngqísì
Yesterday was Thursday.
Keep 星期四 and it comes back until you know it.