Feb 23 2025 Qalculate time hacks

Anarcat recently wrote about Qalculate, and I think I’m a convert, even though I’ve only barely scratched the surface.

The thing I almost immediately started using it for is time calculations. When I started tracking my time, I quickly found that Timewarrior was good at keeping all the data I needed, but I often found myself extracting bits of it and reprocessing it in variously clumsy ways. For example, I often don’t finish a task in one sitting; maybe I take breaks, or I switch back and forth between a couple of different tasks. The raw output of timew summary is a bit clumsy for this, as it shows each chunk of time spent as a separate row:

$ timew summary 2025-02-18 Debian

Wk Date       Day Tags                            Start      End    Time   Total
W8 2025-02-18 Tue CVE-2025-26465, Debian,       9:41:44 10:24:17 0:42:33
                  next, openssh
                  Debian, FTBFS with GCC-15,   10:24:17 10:27:12 0:02:55
                  icoutils
                  Debian, FTBFS with GCC-15,   11:50:05 11:57:25 0:07:20
                  kali
                  Debian, Upgrade to 0.67,     11:58:21 12:12:41 0:14:20
                  python_holidays
                  Debian, FTBFS with GCC-15,   12:14:15 12:33:19 0:19:04
                  vigor
                  Debian, FTBFS with GCC-15,   12:39:02 12:39:38 0:00:36
                  python_setproctitle
                  Debian, Upgrade to 1.3.4,    12:39:39 12:46:05 0:06:26
                  python_setproctitle
                  Debian, FTBFS with GCC-15,   12:48:28 12:49:42 0:01:14
                  python_setproctitle
                  Debian, Upgrade to 3.4.1,    12:52:07 13:02:27 0:10:20 1:44:48
                  python_charset_normalizer

                                                                         1:44:48

So I wrote this Python program to help me:

#! /usr/bin/python3

"""
Summarize timewarrior data, grouped and sorted by time spent.
"""

import json
import subprocess
from argparse import ArgumentParser, RawDescriptionHelpFormatter
from collections import defaultdict
from datetime import datetime, timedelta, timezone
from operator import itemgetter

from rich import box, print
from rich.table import Table


parser = ArgumentParser(
    description=__doc__, formatter_class=RawDescriptionHelpFormatter
)
parser.add_argument("-t", "--only-total", default=False, action="store_true")
parser.add_argument(
    "range",
    nargs="?",
    default=":today",
    help="Time range (usually a hint, e.g. :lastweek)",
)
parser.add_argument("tag", nargs="*", help="Tags to filter by")
args = parser.parse_args()

entries: defaultdict[str, timedelta] = defaultdict(timedelta)
now = datetime.now(timezone.utc)
for entry in json.loads(
    subprocess.run(
        ["timew", "export", args.range, *args.tag],
        check=True,
        capture_output=True,
        text=True,
    ).stdout
):
    start = datetime.fromisoformat(entry["start"])
    if "end" in entry:
        end = datetime.fromisoformat(entry["end"])
    else:
        end = now
    entries[", ".join(entry["tags"])] += end - start

if not args.only_total:
    table = Table(box=box.SIMPLE, highlight=True)
    table.add_column("Tags")
    table.add_column("Time", justify="right")
    for tags, time in sorted(entries.items(), key=itemgetter(1), reverse=True):
        table.add_row(tags, str(time))
    print(table)

total = sum(entries.values(), start=timedelta())
hours, rest = divmod(total, timedelta(hours=1))
minutes, rest = divmod(rest, timedelta(minutes=1))
seconds = rest.seconds
print(f"Total time: {hours:02}:{minutes:02}:{seconds:02}")

$ summarize-time 2025-02-18 Debian

  Tags                                                     Time
 ───────────────────────────────────────────────────────────────
  CVE-2025-26465, Debian, next, openssh                 0:42:33
  Debian, FTBFS with GCC-15, vigor                      0:19:04
  Debian, Upgrade to 0.67, python_holidays              0:14:20
  Debian, Upgrade to 3.4.1, python_charset_normalizer   0:10:20
  Debian, FTBFS with GCC-15, kali                       0:07:20
  Debian, Upgrade to 1.3.4, python_setproctitle         0:06:26
  Debian, FTBFS with GCC-15, icoutils                   0:02:55
  Debian, FTBFS with GCC-15, python_setproctitle        0:01:50

Total time: 01:44:48

Much nicer. But that only helps with some of my reporting. At the end of a month, I have to work out how much time to bill Freexian for and fill out a timesheet, and for various reasons those queries don’t correspond to single timew tags: they sometimes correspond to the sum of all time spent on multiple tags, or to the time spent on one tag minus the time spent on another tag, or similar. As a result I quite often have to do basic arithmetic on time intervals; but that’s surprisingly annoying! I didn’t previously have good tools for that, and was reduced to doing things like str(timedelta(hours=..., minutes=..., seconds=...) + ...) in Python, which gets old fast.

Instead:

$ qalc '62:46:30 - 51:02:42 to time'
(225990 / 3600) − (183762 / 3600) = 11:43:48

I also often want to work out how much of my time I’ve spent on Debian work this month so far, since Freexian pays me for up to 20% of my work time on Debian; if I’m under that then I might want to prioritize more Debian projects, and if I’m over then I should be prioritizing more Freexian projects as otherwise I’m not going to get paid for that time.

$ summarize-time -t :month Freexian
Total time: 69:19:42
$ summarize-time -t :month Debian
Total time: 24:05:30
$ qalc '24:05:30 / (24:05:30 + 69:19:42) to %'
(86730 / 3600) / ((86730 / 3600) + (249582 / 3600)) ≈ 25.78855349%

I love it.