feat(tools/when): simple time-conversion tool r/8090

I often need unix timestamps, or have unix timestamps, or need timestamps at
certain relative offsets etc.

This adds a tool called `when` which can do all of this. It has basically no
user interface, you just call it with a time query and it does it if it
understands what you meant. This will get smarter over time as I find more uses.

Example:

    ~> when yesterday 5PM
    Local: Mon 06 May 2024 at 17:00:00 MSK
    UTC:   2024-05-06T14:00:00Z
    UNIX:  1715004000

It supports all kinds of queries already, see the usage for details.

Change-Id: I694ffef7608586acfb1ff8010ac0fac4d9951e2e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11598
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: tazjin <tazjin@tvl.su>

0 files changed, 0 insertions, 0 deletions