This graph applies to colds, viral infections and influenza.  Important things to take notice of:

1—Only about one in five such infections have an associated fever.  If there is fever, it should be present near the start of the illness.  Fever that persists more than 5 or 6 days become more likely to be something other than a common cold/virus---the longer the fever persists, the more suspicious of something else.

2---Once the fever has been gone 24 or more hours, its return is suspicious of some additional complication (such as an ear infection or sinus infection).

3---Nasal congestion and cough can linger, slowly improving, for up to two weeks with each cold.

4---Children between 6 and 18 months have 5 to 6 colds or viral infections per winter.  If they are in daycare, they have 3 to 4 more.  Considering winter and cold season is about 180  days, children this age have cold symptoms 84 to 140 of those 180 days---about one week well for each with cold symptoms.  Children 18 to 30 months have colds about half this often.  The following year, the frequency is again half that of the prior year and stays at about this level (24 to 45 days per winter) until kindergarten age.