You can either say that you are closed on the weekend, OR you can say that you are only open during the week.
Weekdays mean days from Monday to Friday, so excluding the weekends. You can either say weekdays, or you can say Monday to Friday.
We are open on weekdays but closed on the weekends.
We are closed on Saturday and Sunday
We are not open on the weekends.
Ways to say that a business is closed on weekends are "We are open on weekdays but not weekends.", "We are closed on Saturdays and Sundays." You can use the actual day names instead of saying weekend if you prefer.
週末はビジネスを閉めているということを言う言い方は、
We are open on weekdays but not weekends.
（平日は開けて、週末は閉めています。）
We are closed on Saturdays and Sundays.
（土日は閉めています。）
もしあなたが好むなら、週末という代わりに、曜日を使うこともできます。
Our business days are from Monday to Friday and we are closed during weekends.
The preposition 'during' refers to 'a given period of time', which in this case is the weekend period. You may also add the noun 'business days' during which your company conducts business but is closed 'during' weekends. So, if your company's business days are from Monday to Friday and you are closed during weekends, you may say:
Our company is closed during weekends.
or
Our business days are from Monday to Friday and we are closed during weekends.
「during」という前置詞は、ある「一定期間」を意味し、この場合、週末のことを指します。あなたの会社が開いている時間は「business days」と言え、週末の間閉まります。あなたの会社の開店日が月曜日から金曜日なら週末は閉店しています。以下のように言えるでしょう：
Our company is closed during weekends.
（弊社は週末閉店です。）
Our business days are from Monday to Friday and we are closed during weekends.
（弊社の開店日は月曜日から金曜日で、週末は閉店です。）
**Unfortunately we are closed on Weekends.
Unfortunately= I'm sorry but...
**We open throughout the week & close on weekends.
This is more positive, telling them when you're open first and then adding that you are closed at the weekends.
**We aren't open at the weekends, I'm afraid.
I'm afraid= another polite way of saying sorry.
You could also say...
*We open Monday to Friday only.
*We operate during the weekdays.
*We open Mon to Fri but you can always contact us by...(list your email, phone number, address etc)
Hope this helps! ^ ^
Unfortunately we are closed on Weekends.
（申し訳ないですが、週末は閉店しています。）
Unfortunately=申し訳ないですが。。。
We open throughout the week & close on weekends．
（1週間を通して開店していますが、週末は閉店しています。）
これは、より肯定的な言い方で、最初にいつ開店しているか言い、それから週末閉店していることを付け加えます。
We aren't open at the weekends, I'm afraid.
（申し訳ないですが、週末は閉店しています。）
I'm afraid=申し訳ないことを伝える別の丁寧な言い方です。
以下のようにも言えます。
We open Monday to Friday only.
We operate during the weekdays.
（平日開店しています。）
We open Mon to Fri but you can always contact us by...(list your email, phone number, address etc).
（平日のみ開店していますが、いつでも・・・で連絡できます。）
あなたの理解の助けになれば！^ ^
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