24hr Time Calculations

[Thomas Klemm]

Your program works fine when I copied and pasted it into Free42.
However it shortened the 2nd variable "DAY START" to "DAY STA":

Code:

00 { 48-Byte Prgm }
01▸LBL "TMSHT"
02 INPUT "DAY END"
03 INPUT "DAY STA"
04 RCL "DAY END"
05 RCL "DAY STA"
06 HMS-
07 →HR
08 Σ+
09 END

You get a "Nonexistent" message if the variable isn't created yet but the program wants to access it.
This might happen for instance if the program starts at line 04.

In such a case you can single step through the program with the SST or just the ▼ key.
While you press down the key the current line is displayed:

Code:

03 INPUT "DAY STA"
04▶RCL "DAY END"

HTH