Conditional Formatting with a a formula - I've hit a brick wall with this one

Hey all. I've spent most of my working day trying to resolve this issue. I'd really appreciate some help.


I've made an events timetable for a venue with 15 minute time slots in columns along the top. What I want to do is input the start time of an event into a cell and the end time into a cell - causing the relevant cells below the 15 minute time slots to colorize accordingly i.e. if an event starts at 12 and finishes at 4, I want the cells on the row containing the event name to colorize where those cells are within the column that is headed by one of the 15 minute time slots.

I've been doing this with conditional formatting: =AND(L$2>=$J4,L$2<=$K4) but I'm having an issue. If an event starts at 12 and finishes at 6, I want the cell within the column headed by 12:00 to colorize, and the cell within the column headed by 17:45 to colorize as well as all the cells in between. But what's happening is *sometimes* the cell within the column headed by 11:45 colorize as does the one headed by 18:00. But this only happens with some events despite them all having the same formula (NB: a column headed by 17:45 denotes the time of 17:45 up to and including 18:00. Where the cell within the column headed by 18:00 colorizes, it looks like the event carries on to 18:15. It seems to be particularly happening the most for events that run on after 4pm.

Really need help with this!

Try removing the last = from your rule formula so that it reads as

Formula:

=AND(L$2>=$J4,L$2<$K4)