Web app updated from PHP 5.4 to 7

a timesheet app with associated static pages need updated from PHP v5.4 to v 7. no database updates as that'll be done elsewhere. Front end web page update only. the main timesheet page is involved having levelled functionality, other 5 or so static pages are basic CRUD. Most of the work is updating the db connection and other 5->7 updates across the pages. The whole app is based on an existing framework from the build time. It'll be tested silly to ensure its good, so ensure adequate accounting is included in costing.