Jīntiān jiù dào zhèr ba.
今天就到这儿吧。
Let's call it a day.
Notes:
今天(jīntiān): today
就(jiù): just
到这儿(dào zhèr): stop here
吧(ba): a particle word shows the whole setence is a suggestion
Example:
A:今天就到这儿吧。
Jīntiān jiù dào zhèr ba.
Let's call it a day.
B:老师再见。
Lǎoshī zàijiàn.
Bye, teacher.