Day Before Last
Day Before Yesterday
noun
Remember how you learned that 昨日 means "yesterday?" Well one day previous to that day is the day before last.
This reading is an exception. Let's use this mnemonic to remember it:
The day before last you bought an "O" toe toy (おととい). It's a kid's toy in the shape of the letter O that you put on your toe. You know it was the day before last because you wore it all yesterday, and now today your toe is sore. If only you could go back to the day before yesterday to tell yourself not to buy that O toe toy! Or at least not to wear it for the whole next day!
今さらですが一昨日の5月5日はルフィのたん生日でした。
It's a bit late, but the day before yesterday, May 5, was Luffy's birthday.
一昨日だったら空いてたんだけど、今月は他の日は全てうまってしまってるんだよね。
I was available the day before last, but this month all of my other days are entirely full already.
一昨日、夫の不倫現場を見てしまったんです。
The day before last I caught my husband cheating on me.