Conditional formatting is one of those features that seems simple until it isn't. The user in this post did everything right, checked that the date column was formatted as dates, used `=TODAY()` for today's reference, and still watched their cells refuse to turn yellow or red. That frustration is familiar to anyone who has spent an afternoon chasing a formula that should work but doesn't. And the fact that their post was removed by moderators only adds insult to injury. But here's the thing: when conditional formatting fails, the problem is almost never the formatting itself. It's the rules.
The most common culprit is a mismatch between what you *think* the rule is doing and what the rule is *actually* doing. For example, the user mentioned checking that the date column is formatted as Date, but Excel's date formatting and the underlying serial value are two different things. If your formula references a cell that contains a date entered as text, or if the rule is applied to the wrong range, or if the rule's "Applies to" area doesn't match the cells you're looking at, you'll get nothing. No error, no highlight, just silence. The user said they checked "making sure it's Date in all date column," but did they check whether the rule's formula uses absolute references correctly? A rule like `=$A1=TODAY()` behaves differently than `=A1=TODAY()` when applied across a range. That single dollar sign can be the difference between a working rule and a dead one.
What's striking here is that the user did the right thing by verifying their assumptions. They didn't just assume the data was correct, they checked. But checking the data isn't the same as checking the logic. Conditional formatting in Excel is unforgiving about context: it evaluates each cell relative to the top-left cell in the selected range. If your formula is written for the wrong reference point, every cell will evaluate incorrectly. The user's mention of `=TODAY()` also hints at another subtlety: `TODAY()` is a volatile function, but that's not the issue. The issue is whether the rule is set to "Cell Value" or "Formula." If it's set to the former, you're limited to simple comparisons. If it's set to the latter, you have full control, but only if the formula is written correctly for the active cell.
So what does this mean for you? It means that when conditional formatting doesn't work, stop rechecking the data and start rechecking the rule. Highlight the entire range you want to format, then create the rule with the active cell in mind. If you're using a formula, make sure it's relative where it should be and absolute where it shouldn't. And if you're comparing dates, remember that Excel stores them as numbers, so a text-formatted date will never match a real date, no matter how it looks. The user's post is a perfect example of why we need to move past the surface-level checks. The answer isn't to give up on conditional formatting. It's to understand that the rules are literal, and they will only do what you tell them, no more, no less. Start by selecting your range, writing the formula for the active cell, and testing it with a single cell before applying it broadly. That's the difference between guessing and knowing.