A ten-year time capsule

Why is ten years different from one?

After a year you remember writing the capsule, and most of the context is still around. After ten you may not remember it exists. You will have different devices, perhaps a different city and certainly different friends in your top five. Plan the capsule for someone who is partly a stranger.

The Wikipedia article on digital preservation lists the risks of long storage, among them media failure and obsolete formats, and the same list applies to your phone.

What should I write for a decade-later reader?

Treat it as a letter to a close relative who has been out of touch.

• The date, your age and a short description of a normal day.
• Who the people are, with their relationships and nicknames.
• The state of your work, home, money in general terms and health in general terms.
• What you are afraid of and what you hope for.
• Five guesses about the open date, each checkable.
• A list of the objects you use every day: phone model, car, brand of coffee.
• What costs what: rent, a coffee, a bus ride.
• A question you want your future self to answer.

Explain the obvious. In ten years the obvious has disappeared.

How do I keep it small?

A long capsule gets skimmed. Aim for one letter, five guesses, three photos and one voice note. In Sealday a free capsule holds up to ten guesses, one photo and a 30-second voice note, and Plus raises these to 30 guesses, 30 photos and five minutes of voice. You can always add a second capsule with a different date.

Sealday shows a note when you pick a date more than ten years away, so you read the limits before you commit. They are listed on the time lock page.

How do I back it up for a decade?

The routine is covered in backup and restore and in how to keep digital memories safe.

1. Seal the capsule and note the date in two calendars.
2. Export a vault file from You > Backup and restore.
3. Save the file to iCloud Drive and to a drive that is not at home.
4. Keep iCloud Backup on for the iPhone.
5. Each December, export a fresh file and check that the old one still opens.
6. Tell one trusted person where the file is kept.

What are the honest limits?

The lock holds as long as drand keeps publishing. If the beacon network ever shut down for good, capsules you sent to someone else could not be opened. Your own capsules would still open on that iPhone with the spare key, after the open date has passed and the beacon has been unreachable for 72 hours. A capsule restored on a new phone has no spare key, which is why backups matter.

The other limits are ordinary ones: devices fail, files get deleted, and people forget. They are the reason for the yearly check.

What would I regret not including?

People who open old letters say the same few things. They wish they had described the people in more detail, named the small rituals, recorded a voice and written down what things cost. They rarely wish for more advice, and almost never for more adjectives.

So put in your friends' names and how you met them. Describe the Sunday routine. Record 30 seconds of the room. Photograph the fridge and the street. Mention one thing that annoys you daily and expect it to be gone. A ten-year gap makes a mundane object into an artifact, and the mundane objects are the ones you will miss most.

Should I make a ten-year capsule or ten one-year capsules?

Ten one-year capsules teach you more and fail more gracefully. If one goes missing you lose a year, not a decade. A ten-year capsule has a stronger sense of occasion. The best answer is both: a yearly New Year capsule in the background and one bigger letter at a turning point.

A ten-year capsule also suits a child. See baby time capsule ideas for letters that open at thirteen or eighteen, and how long should a time capsule stay sealed for the trade-offs.