tcalc

Evaluate temporal arithmetic expressions, i.e. calculate time sums and differences.

A spontaneous hack at 11 p.m. with error handling to match.

Usage

1. Run
2. Enter expression on stdin
3. Get result
4. Repeat
5. Enter an empty line (or EOF) to quit

Expression format, operators

Time formats:

• "Time", e.g. 14:02.
• "Minute", e.g. 31.

Operators (in decreasing order of precedence):

• . — calculate difference between two times.
  .., ..., etc are also valid.
  If the second operand is smaller than the first, a midnight crossing is assumed and calculated.
• + and - — add / subtract.
  Expect two operands. Each operand can be a time or a minute.

Verbose mode:

• Append a ? (or multiple) to an expression to enable verbose mode.
  Verbose mode prints all intermediate values as they are calculated.

Examples

1
0:01

9:00..17:00
8:00

9:00..17:00-35
7:25

20:15+1:30
21:45

20:15+90
21:45

20:15+3:50
24:05

9:15..18:41-44+2:31+19
11:32

9:15..18:41-44+2:31+19?
. 9:15 to 18:41 = 566 minutes (9:26)
> 2:31 = 151 minutes (2:31)
< 566 minutes = 566 total (9:26)
- 44 minutes = 522 total (8:42)
+ 151 minutes = 673 total (11:13)
+ 19 minutes = 692 total (11:32)
11:32