One formula work, but not always.

[wkirkcrawford]

Greetings,

I'm creating a Log of my Blood Sugar Readings.

I am checking the last time that I took a shot. Not all lunchtime do I take a shot.

Here's what I started with; =IF(AC10="","",IF(U10<>"",MOD(AA10-I10,1),MOD(AA10-R10,1))) AC10 is current reading, U10 does the VLOOKUP, results could be 2 to 7. AA10 is current time, I10 is the time I took my shot in the morning. R10 is lunchtime that I should take a shot, but sometimes I don't take a shot.

With this current Formula a blank cell, U11, results in 'VALUE'. It should check, MOD(AA11-R11,1).

I'm using a Surface RT and Office came with it.

W. Kirk Crawford
Tularosa, New Mexico

 

[FDibbins]

Hard tyo say for sure, but chect that the cells that contain dates/times, actually do contain dates and times, and not just text that looks like a date/time (I am assuming that because you are using MOD() there is a date attached to the time?)

Test for valid date/time by using =ISNUMBER(cell-ref) FALSE indicates text

 

[wkirkcrawford]

Never mind. I figured the difference between <>"" and ="" and ISBLANK.

I figured it out.

W. Kirk Crawford
Tularosa, New Mexico

 

[wkirkcrawford]

Ford,

No, I checked that already.

Thanks.

W.Kirk Crawford
Tularosa, New Mexico

 

[FDibbins]

I figured the difference between <>"" and ="" and ISBLANK.

="" and ISBLANK(cell-ref) should produce the same answer on a blank cell

<>"" is just the opposite, it will return TRUE for a cell that is not blank (and this includes a cell with a formula in it)

so ="", ISBLANK(cell-ref) and =NOT(<>"") are all the same thing