# Unix Timestamp Intuition
Let's get a date and its corresponding [unix
timestamp](https://en.wikipedia.org/wiki/Unix_time).
```
dt=$(date --iso-8601=s)
echo "$dt --> $(date +%s --date=$dt)"
2022-04-07T11:28:04+02:00 --> 1649323684
```

The number `1649323684` is composed of 10 digits, each one representing a power
of 10 for seconds, but what does that mean in human time?

```{csv-table}
position,pow(10),seconds since 1970,approximate human time
1,9,1000000000,31 years
2,8,100000000,3 years
3,7,10000000,3 months
4,6,1000000,11 days
5,5,100000,a day
6,4,10000,2 hours
7,3,1000,16 minutes
8,2,100,a minute
9,1,10,10 seconds
10,0,1,a second
```

For example increasing the second digit from 6 to 7 moves the timestamp 3 years
into the future:
```
$ date --utc --iso-8601=s --date=@1649323684
2022-04-07T09:28:04+00:00

$ date --utc --iso-8601=s --date=@1749323684
2025-06-07T19:14:44+00:00
```

## Min & Max Timestamps with 10 Digits
```
$ date --utc --iso-8601=s --date=@0000000000
1970-01-01T01:00:00+00:00

$ date --utc --iso-8601=s --date=@9999999999
2286-11-20T17:46:39+00:00
```



## Notes
- zip does not like unix time 0
  https://blog.izs.me/2021/10/my-favorite-npm-commit/


## Code
To generate the above table using
[humanize](https://github.com/jmoiron/humanize):
```
import humanize
import datetime as dt

DIGITS = 10

for pos in range(1, DIGITS+1):
    pow10 = DIGITS - pos
    total_s = DIGITS**pow10
    human = humanize.naturaldelta(total_s)
    print(','.join([str(x) for x in [pos, pow10, total_s, human]]))
```

This code is good enough for this simple one-off use-case. The
~~Over-Engineer~~ Software-Engineer in my mind says:

- use functions!
- use yield!
- use csvwriter!
- output at the end!
- import structlog :D