到……为止: up to, as of
【五27】固定格式 / fixed patterns
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
到……为止 picks a point in time and sums up what has been true up to it: 到目前为止, 到现在为止, 到上个月底为止. Put the time between 到 and 为止, then give the finding, often with 已经, 一共 or 还没有.
The sentence looks backwards from that point: it summarises the past and never predicts. Do not mix it up with 以前 ("before a given time", no summing up) or with the verb 到 ("arrive"). It also marks a limit: 报名到星期五为止 (registration closes on Friday).
到此为止 (or 到这里为止) means "let's stop here": it closes a meeting, a talk or a discussion. Neutral register, very common in business figures, presentations and reports.
Examples
到现在为止，我还没有收到他的回信。
Dào xiànzài wéizhǐ, wǒ hái méiyǒu shōudào tā de huíxìn.So far I haven't had a reply from him.
到目前为止，这个软件的用户已经超过十万了。
Dào mùqián wéizhǐ, zhège ruǎnjiàn de yònghù yǐjīng chāoguò shí wàn le.As of now, this software has more than a hundred thousand users.
到去年年底为止，他们已经在全国开了二十多家店。
Dào qùnián niándǐ wéizhǐ, tāmen yǐjīng zài quánguó kāi le èrshí duō jiā diàn.By the end of last year they had already opened more than twenty shops across the country.
报名时间到这个星期五为止，没报名的同学请抓紧时间。
Bàomíng shíjiān dào zhège xīngqīwǔ wéizhǐ, méi bàomíng de tóngxué qǐng zhuājǐn shíjiān.Registration runs until this Friday; those who haven't signed up, please hurry.
我们今天的讨论就到此为止，大家回去再想一想。
Wǒmen jīntiān de tǎolùn jiù dào cǐ wéizhǐ, dàjiā huíqu zài xiǎng yi xiǎng.That's all for today's discussion; everyone go home and think it over.
Common mistakes
✗ 到目前，我们已经有十万用户 → ✓ 到目前为止，我们已经有十万用户 (为止 is required, 到目前 alone is not enough).
✗ 到现在为止，我们明年会开新店 → ✓ 到现在为止，我们已经开了三家店 (it sums up the past, it does not predict the future).