Setting time in scatter chart

[M_Timps]

Hey! Doing some stuff with charts. Im having trouble getting time to show on Y axis the way I want. My time period starts at 12:17:00 and ends at 7:41:45 - so yes every second and almost 70 000 data points + the 24h format, not AM/PM. I know I have to set the minimum,maximum, major units,minor units from axis option but I simply cant get it right. Help would be appreciated.

 

[thisoldman]

You're crossing midnight.
12:17:00 on day zero is 0.5118 as a general format number.
07:41:45 of the next day, nineteen and a half hours later, is 1.32066 as a general format number.

When you cross midnight, you have to increase the integer portion of the time-date number by one to keep the correct sequence of time values.

 

[thisoldman]

I didn't answer all your questions. Dates and times in Excel are represented as decimal numbers. Hours, minutes, and seconds are fractional parts of a day

A full 24-hours, one day, is 1.0. Twelve hours, a half-day, is 0.5.
One hour is one twenty-fourth of a day. As an Excel formula, that's =1/24 or ~0.04167.
One minute is one sixtieth of an hour, =1/24/60 or =1/1440 or ~0.000694.
One second is one sixtieth of a minute =1/24/60/60 or 1/86400 or ~1.157E-05.

You have to calculate times as fractional parts of a day. To convert 15 minutes to an Excel time:

15 min ÷ 60 min/hr ÷ 24 hr/day
​

or

15 min ÷ 1440/day
​

Excel formula:
=15/1440

Working with time in Excel starts off being a pain. The pain subsides and working with times becomes an annoyance. It sharpens to being a g*****n annoyance when you know how easy working with times and timestamps are in Unix and Linux (Google "Unix epoch").