Skip to content
Snippets Groups Projects

unixtime-anniversaries

  • Clone with SSH
  • Clone with HTTPS
  • Embed
  • Share
    The snippet can be accessed without any authentication.
    Authored by clonejo
    unixtime-anniversaries.py 4.17 KiB
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94
    95
    96
    97
    98
    99
    100
    101
    102
    103
    104
    105
    106
    107
    108 
    #!/usr/bin/python3

# Calculate unix timestamps that are multiples of powers of 2 and 10 (or n).
#
# ## Gotchas
# - Displayed times are localtime, unfortunately. Timestamps should be OK
#   though.
#
# ```sh
# ./unixtime-anniversaries.py
# ```
#
# ```
# now:                  1600348680 2020-09-17 15:18:00.999827
# base 10000000 (10**7):
#     last anniversary: 1600000000 = 10**7 * 160 = 2020-09-13 14:26:40
#     next anniversary: 1610000000 = 10**7 * 161 = 2021-01-07 07:13:20
# base 100000000 (10**8):
#     last anniversary: 1600000000 = 10**8 *  16 = 2020-09-13 14:26:40
#     next anniversary: 1700000000 = 10**8 *  17 = 2023-11-14 23:13:20
# base 1000000000 (10**9):
#     last anniversary: 1000000000 = 10**9 *   1 = 2001-09-09 03:46:40
#     next anniversary: 2000000000 = 10**9 *   2 = 2033-05-18 05:33:20
#
# base 8388608 (2**23):
#     last anniversary: 1593835520 = 2**23 * 190 = 2020-07-04 06:05:20
#     next anniversary: 1602224128 = 2**23 * 191 = 2020-10-09 08:15:28
# base 16777216 (2**24):
#     last anniversary: 1593835520 = 2**24 *  95 = 2020-07-04 06:05:20
#     next anniversary: 1610612736 = 2**24 *  96 = 2021-01-14 09:25:36
# base 33554432 (2**25):
#     last anniversary: 1577058304 = 2**25 *  47 = 2019-12-23 00:45:04
#     next anniversary: 1610612736 = 2**25 *  48 = 2021-01-14 09:25:36
# base 67108864 (2**26):
#     last anniversary: 1543503872 = 2**26 *  23 = 2018-11-29 16:04:32
#     next anniversary: 1610612736 = 2**26 *  24 = 2021-01-14 09:25:36
# base 134217728 (2**27):
#     last anniversary: 1476395008 = 2**27 *  11 = 2016-10-13 23:43:28
#     next anniversary: 1610612736 = 2**27 *  12 = 2021-01-14 09:25:36
# base 268435456 (2**28):
#     last anniversary: 1342177280 = 2**28 *   5 = 2012-07-13 13:01:20
#     next anniversary: 1610612736 = 2**28 *   6 = 2021-01-14 09:25:36
# base 536870912 (2**29):
#     last anniversary: 1073741824 = 2**29 *   2 = 2004-01-10 14:37:04
#     next anniversary: 1610612736 = 2**29 *   3 = 2021-01-14 09:25:36
# base 1073741824 (2**30):
#     last anniversary: 1073741824 = 2**30 *   1 = 2004-01-10 14:37:04
#     next anniversary: 2147483648 = 2**30 *   2 = 2038-01-19 04:14:08
#
#
# ```sh
# ./unixtime-anniversaries.py | grep next | sort >> README.md
# ```
#
# ```
#     next anniversary: 1602224128 = 2**23 * 191 = 2020-10-09 08:15:28
#     next anniversary: 1610000000 = 10**7 * 161 = 2021-01-07 07:13:20
#     next anniversary: 1610612736 = 2**24 *  96 = 2021-01-14 09:25:36
#     next anniversary: 1610612736 = 2**25 *  48 = 2021-01-14 09:25:36
#     next anniversary: 1610612736 = 2**26 *  24 = 2021-01-14 09:25:36
#     next anniversary: 1610612736 = 2**27 *  12 = 2021-01-14 09:25:36
#     next anniversary: 1610612736 = 2**28 *   6 = 2021-01-14 09:25:36
#     next anniversary: 1610612736 = 2**29 *   3 = 2021-01-14 09:25:36
#     next anniversary: 1700000000 = 10**8 *  17 = 2023-11-14 23:13:20
#     next anniversary: 2000000000 = 10**9 *   2 = 2033-05-18 05:33:20
#     next anniversary: 2147483648 = 2**30 *   2 = 2038-01-19 04:14:08
# ```

from datetime import datetime


def anniversaries(now, interval_str):
    interval = eval(interval_str)
    last_anniversary_factor = int(now.timestamp()) // interval
    last_anniversary = datetime.fromtimestamp(last_anniversary_factor * interval)
    print(f"base {interval} ({interval_str}):")
    print(
        f"    last anniversary: "
        f"{int(last_anniversary.timestamp())} = "
        f"{interval_str} * {last_anniversary_factor:>3} = "
        f"{last_anniversary}"
    )
    next_anniversary_factor = int(now.timestamp()) // interval + 1
    next_anniversary = datetime.fromtimestamp(next_anniversary_factor * interval)
    print(
        f"    next anniversary: "
        f"{int(next_anniversary.timestamp())} = "
        f"{interval_str} * {next_anniversary_factor:>3} = "
        f"{next_anniversary}"
    )


now = datetime.now()
print(f"now:                  {int(now.timestamp())} {now}")

anniversaries(now, "10**7")
anniversaries(now, "10**8")
anniversaries(now, "10**9")
print()

anniversaries(now, "2**23")
anniversaries(now, "2**24")
anniversaries(now, "2**25")
anniversaries(now, "2**26")
anniversaries(now, "2**27")
anniversaries(now, "2**28")
anniversaries(now, "2**29")
anniversaries(now, "2**30")
    0% or .
    You are about to add 0 people to the discussion. Proceed with caution.
    Finish editing this message first!
    Please register or to comment