Year 2038 Problem (Y2K38)

The Year 2038 Problem is caused by how some software systems store dates.
Most software that uses a signed 32-bit integer for time will overflow after this exact moment:

One second later, many systems will wrap around to:

Bitcoin stores the timestamp in the block header.

If we store this date using 31 bits, we run out of space precisely at:
2038-01-19 03:14:07

Luckily, Bitcoin stores timestamps as 32-bit unsigned integers,
giving us time until the year 2106.

Fixing this isn’t a small update, it will likely require a hard fork.

The timestamp is part of the block header, which means any change affects the block hash itself.

👉 Follow @bitcoin_devs for more Bitcoin technical