Cough - I took Tylenol - Severe Sinus 4 hours ago, I now only have DayQuil at my work, is it okay to

I'm not exactly sure about the content of acetaminophen in Tylenol Sinus and DayQuil. The recommended dose of acetaminophen is 1g (usually 2 x tablets containing 500mg acetaminophen) every 4 to 6 hours when required, but not more than 4g of acetaminophen in 24 hours.

So you should be fine to take Dayquil after 4 hours of taking Tylenol.