dte 0.2.1

Date Time Expressions

Date Time Expression

dte is a WIP date-time processing language with focus on broad interpretation.

If you don't think it's intuitive, it's most likely unfinished.

It is strongly inspired by pdd.

How to use & What to know

pip install dte

Conventions

• When there is margin for ambiguity, expressions are always interpreted with highest units appearing before, complying with ISO-8601, e.g.: 2021-06-13, 2023 August 27 or 2019 Jul 20
• Unix timestamps are both interpreted and output in seconds by default, but this is configurable
• When specifying time, just remember that M is for month and m is for minute

Configuration File

dte tries to read a config.json file under config directory (~/.config/dte/ on Linux). In it you can set the following options:

{
  "timestamp_unit": "<seconds|milliseconds>"
  "clock": "<24|12>",
  "datetime_output_format": "<ISO8601|<format>>",
  "comparison_tolerance_seconds": <float>,
  "basedate_output_format": "%Y-%b",
  "decimal_places": <integer>
}

Dependencies

• dateutil handles month and year's complex operations
• ply is a pure-Python implementation of the popular compiler construction tools lex and yacc
• appdirs for reading config file in a cross-platform manner

To do

• in keyword
  • first/last friday in 2014 - extremity
  • first/last friday in April - extremity
  • first/last friday in next month - extremity
  • first/last friday in 2014 April - extremity
  • INTEGERth WEEKDAY IN BASEDATE - extremity?
• format(timepoint, fmt) (in keyword) units given current time field
• add custom/OS locale support (?)
• add tab-completion for:
  • months
  • units given current datetime field or RHS of in keyword
• decide whether UNIT (SINCE/UNTIL) TIME should return negative values; in other words: should "hours until 1am" when n=11pm be interpreted to t+1d 1am or t 1am
• run tests across a variety of locales
• add show function
  • show clock for time
  • show cal for date and basedate

Examples

The following examples are generated based on tests run, so many results will be relative to the day it was tested. Every expression on the left side is valid syntax.

(T-1d).weekday returns Tuesday

(n + 180d)-180d == n returns True

(n + 181d)-180d != n returns True

(t + 180d)-180d == t returns True

-1d.weekday returns Tuesday

08h30 returns 8:30:00

1 in unix returns 1

n - 1234 returns 18913 days, 22:19:48.912292

10h30 + 14h returns 1 day, 0:30:00

2021 feb 14 12:00:00 returns 2021-02-14 12:00:00

seconds until 2021 feb 14 12:00:00 returns -20850023.163074

1-1-1 23:23:23 returns 0001-01-01 23:23:23

1-1-1 23:23m returns 0001-01-01 23:23:00

1-1-1 23h:23 returns 0001-01-01 23:23:00

1-1-1 23h:23m returns 0001-01-01 23:23:00

1-1-1 23m:23 returns 0001-01-01 00:23:23

1-1-1 23m:23s returns 0001-01-01 00:23:23

1-1-1 23m:23S returns 0001-01-01 00:23:23

1-1-1 23:23S returns 0001-01-01 00:23:23

11h:20 AM returns 11:20:00

11m:20 PM returns 00:11:20

11h:20 am returns 11:20:00

11h:20m pm returns 23:20:00

11:20s PM returns 00:11:20

2014 Jan 13 returns 2014-01-13

2014 January 13 returns 2014-01-13

1996.04.28 returns 1996-04-28

22h:22 returns 22:22:00

22:22:22 returns 22:22:22

22h:22m:22 returns 22:22:22

22h:22m:22s returns 22:22:22

22:22m:22s returns 22:22:22

22h:22:22s returns 22:22:22

22:22:22s returns 22:22:22

2020-Jan-27 returns 2020-01-27

6 pm returns 18:00:00

6 pm + 1h returns 19:00:00

6pm returns 18:00:00

22m:22 + 4h returns 4:22:22

1-1-1-1-1-1 returns 0:00:00

1610494238 returns 2021-01-12 20:30:38

1610494238+4h.weekday returns Wednesday

1610494238.weekday returns Tuesday

12h:00 AM != 12h:00 PM returns True

2014 Jan 13==2014 January 13 returns True

1957-12-26 - t returns -23302 days, 0:00:00

1957-12-26 22:22:22 - t returns -23302 days, 22:22:22

1958-05-14 - 1958-05-16 returns -2 days, 0:00:00

1d in hours returns 24.0

1d in minutes returns 1440.0

1d in seconds returns 86400.0

1d returns 1 day, 0:00:00

1d+0h22m returns 1 day, 0:22:00

1d1m in hours returns 24.016666666666666

1970 Jan 1 - 3h in unix returns 0

1w returns 7 days, 0:00:00

2020 Jan 27 + 1y == 2021 Jan 26 returns True

2 < 1 returns False

12h:00 pm != 12h:00 am returns True

22h+2m returns 22:02:00

22h22m returns 22:22:00

6y5M4d3h2m1s returns 2346 days, 3:02:01

7y6M5w4d3h2m1.1s returns 2778 days, 3:02:01.100000

2h2m returns 2:02:00

3h+3M returns 92 days, 3:00:00

3M returns 92 days, 0:00:00

T-1.5d returns 2021-10-11 12:00:00

T-10d returns 2021-10-03

T.day returns 13

T.weekday returns Wednesday

YD.day returns 12

n returns 2021-10-13 19:40:28.140041

next Sunday returns 2021-10-17

2000-10-10 00:16 returns 2000-10-10 00:16:00

2000-10-10 16:00 returns 2000-10-10 16:00:00

seconds until 3000 Apr 10 returns 30878079571.543015

seconds since 3000 Apr 10 returns -30878079571.460346

next Sunday == last sunday returns False

next Sunday != last sunday returns True

last Sunday == next sunday returns False

last Sunday != next sunday returns True

last sunday in 2021 returns 2021-12-26

first sunday in 2021 returns 2021-01-03

1st sunday in 2021 returns 2021-01-03

2012-12-13-3y.weekday returns Sunday

t - next Sunday returns -4 days, 0:00:00

wait .001s returns ``

weekday 0 returns Wednesday

Jan 2014 returns 2014-Jan

first friday in April 2014 returns 2014-04-04

1st friday in April 2014 returns 2014-04-04

first sun in April 2021 returns 2021-04-04

1st sun in April 2021 returns 2021-04-04

yd-5h returns 2021-10-11 19:00:00

1957-12-26 22:22:22 in unix returns -379118258

5m+5m returns 0:10:00

1h in seconds returns 3600.0

1 hour in seconds returns 3600.0

2s2s returns 0:00:04

1996 August 28 9 AM returns 1996-08-28 09:00:00

seconds until tomorrow returns 15569.556429

seconds until 11 pm returns 11969.483238

next month returns 2021-11-01

first friday in next month returns 2021-11-05

1st friday in next month returns 2021-11-05

first friday in april returns 2021-04-02

1st friday in april returns 2021-04-02

2014 01 returns 2014-Jan

6pm+1h returns 19:00:00

days until 2030-12-25 returns 3359.1801948897682

last fri in 2014 December returns 2014-12-26

last fri in 2014 Dec returns 2014-12-26

last fri in Dec 2014 returns 2014-12-26

yesterday==thursday returns False

yesterday==thu returns False

weekday tm returns Thursday

(weekday t+100d) returns Friday

(weekday t+100d)==100d.weekday returns True

weekday t+100d returns Friday

monday+1d returns 2021-10-12

next mon + 1d returns 2021-10-19

next mon + 1d == next tue returns True

days until next mon returns 4.180183002824074

days until mon returns -2.81981790900463

today==mon returns False

seconds in 24h returns 86400.0

Jan 2014 + 1M returns 2014-02-01

2014 Jan + 1M returns 2014-02-01

-1d + 2020-10-10 returns 2020-10-09

2nd sunday in 2021 returns 2021-01-10

3rd sunday in 2021 returns 2021-01-17

4th sunday in 2021 returns 2021-01-24

5th sunday in 2021 returns 2021-01-31

4th wed in august returns 2021-08-25

august returns 2021-Aug

t 1am returns 2021-10-13 01:00:00

t 1:00 returns 2021-10-13 01:00:00

t 1:00 == t 1am returns True

(2020-10-10+1d) 3pm returns 2020-10-11 15:00:00

1am t returns 2021-10-13 01:00:00

1am t == t 1am returns True

t+1d 08h30 returns 2021-10-14 08:30:00

april+1M returns 2021-05-02