iPhone holiday calendar off by 1 day

What calendar are you using that has the holiday(s) in it?

You are replying to a ten month old post, so you will have to provide us details as to what is your issue specifically. Is it a calendar entry you entered yourself that is out by one day? Is it a holiday calendar you added that has an incorrect holiday?

I have a similar problem on my SE. Calendar takes every birthday from my contacts and displays them one day in advance. I thought it possibly had something to do with last year being Leap Year, but same problem this year.

Hi. I had the same issue after restoring my iPhone today. Try this, it worked for me:

Change your location to a different country(try a country that has different holidays. ex: Turkey), open the calendar, change your location back to default. If it didn't work repeat the process.

For my case the holidays were on time but the events like birthdays were still messed up. So I opened my birthday and changed it to a different date and again back to normal. You can repeat this too if it's not working.

By the way, my phone was connected to the computer during this process so it is possible that it just synced from iTunes.

I had the same issue and the above fix switching off automatic and entering my time zone then switching back to automatic worked. Weird but oh well, it's fixed. Thank you.

Be sure Settings > General > Date & Time > Set Automatically = "On"

Also be sure Settings > Mail, Contacts, Calendars > [scroll down to] Time Zone Override = "Off"

If both these are correct, reset the iPhone. Hold the on/off and home buttons together for about 10 seconds until the Apple logo appears.

No

This doesn't work, this is a very frustrating issue!

Which location setting did you change? Settings->?

My SE is also doing this (all holidays are listed 1 day ahead of where they should be).