Your booking rate is worst on the hottest afternoon of the year
The hours you most want to convert are the hours you convert least, and almost nobody has looked at it by hour.
Pull the call log for last summer and break it down by hour and day of week. Count answered, abandoned and sent to voicemail. The pattern is usually the same narrow window across every hot week, and usually nobody in the building has seen it.
The fix is rarely a website change. It is staffing that window, or an overflow service with a real script and access to book, or an automatic text reply that goes out within seconds of a missed call and keeps the person from dialing the next result.
Set a callback standard for missed calls and hold someone to it. Minutes, not hours. A homeowner with no cooling in July is calling three companies and stopping at the first live voice.
Then test it yourself. Call your own number at four on a hot Friday and at nine on a Saturday night. Whatever happens is what happens to every paid click you bought that week.