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### DM15L - difference between two dates?

Posted: **Fri Jun 22, 2018 3:34 pm**

by **jthole**

One function that I regularly use on my HP 12C (next to simple arithmetic and statistics) is "Delta Days". While I really like the DM15L, missing this function (plus the option to substract or add a number of days to a given date) keeps me from using it as my work calculator.

I know there is a DM12L

but a nicer option would be to have an implementation of the "Delta Days" function for the HP 15C. I am aware of some programs that compute a Gregorian date to a Julian date. However, I don't know about a program which does what the HP 12C can; pushing two dates on the stack, and returning the number of days between them.

Anyone aware of such a program, or one that could easily be adapted to the HP 15C / DM15L?

Thanks!

### Re: DM15L - difference between two dates?

Posted: **Fri Jun 22, 2018 6:59 pm**

by **dlachieze**

### Re: DM15L - difference between two dates?

Posted: **Sat Jun 23, 2018 11:41 am**

by **jthole**

Very nice, thank you!

### Re: DM15L - difference between two dates?

Posted: **Sun Jul 15, 2018 5:13 pm**

by **jthole**

Quick update; there are many good things to the HP 12C for me, even when I hardly use any of the financial functions:

- Several data calculations (date plus days, difference between days, day of the week)
- Percentage functions are available as primary functions on the keys
- Statistical functions are in the same place as on the 15C
- 12x and 12/ functions are sadly missing from the 15C (difference is only one keystroke, but those keys are in my muscle memory )

So while I'd love to use the DM15L as my primary calculator, I have to admit that the 12C layout works better for me. Which means that the 12C is back on my desk, while the DM15L is at home as a fun calculator.

So the next questions is of course ... should I splurge on a DM12L or keep using my Singapore made HP 12C until it dies?

### Re: DM15L - difference between two dates?

Posted: **Sun Jul 15, 2018 6:29 pm**

by **rprosperi**

jthole wrote: ↑Sun Jul 15, 2018 5:13 pm

So the next questions is of course ... should I splurge on a DM12L or keep using my Singapore made HP 12C until it dies?

The DM12L is much faster than older (3-battery or 1-battery) 12Cs, so if you use programs this may be a strong factor to consider. I'm not sure of the relative performance of the DM12C as compared to the newest 2-battery machines (often called the 12C+), these are literally over 100 times faster than the older 12Cs. Also, the DM12C has the clock built-in, which may be useful too.

Also, life is short... splurge when you can!