Ad visibility throughout the day
Welcome to the community. It completely depends on your historical data, if you have. For this, you have to monitor your ad very closely. Under 'Dimensions' tab you may find this information. You will find hour-wise details. This will help you understand the click pattern of your ad based on the time. This will help you decide better ad schedule.
I hope this helps.
Re: Ad visibility throughout the day
Do deep analysis on your ad behaviour as Kapil suggested. Analyse your ad performance in Hour basis. It will help you to get the pick hours and you are getting best results. Also you may stop or pause your ad in few hours where you are not getting more impressions and clicks.
Hope it can help you.
In addition to above responses, I would like to add that there is one important factor which comes into picture when you talk about running ads whole day and that's the budget. If you or your client is comfortable with the extended budget, then you can run your ads whole day and increase it based on the need of the day.
Also make sure your campaign Sub- type is All Features (https://support.google.com/adwords/answer/2567043?hl=en) and not standard because Standard campaign type doesn't offer Ad Scheduling for you.
As said above, running the Hour of the Day Report from the Dimensions Tab is certainly a wise decision to see how your ads are performing during each hour of the day and based on those statistics, you can schedule your ads.
My 2 cents!