SQL Queries to calculate dates

Validate and change the start dates in startdate column of tblSchedule_Tasks by querying the enddate of the predecessor task. If the predecessor is 0 the start date remains the same. If the predecessor is 20 for example, you will need a sub query taskNumber = 20 EndDate and change the start date to the taskNumber 20 enddate + 1 day. Each start date needs to be validated against tblHoliday:HolidayDates If the start date is a Saturday add two days to make if Monday If the start date is Sunday add one day to make it Monday. complete sql query that calculates enddate from Startdate + duration. Omitting weekend days and dates from tblHolidays. The query must start with the actual start date then add the duration. For example, if the start date is Monday with a duration of of 1 day the end date is Monday. If the start date is Monday with a duration of 2 days the enddate is Tuesday. You need to test the query for calculated end dates of Friday (there seems to be issues landing on Friday). Need testing for duration of up to 35 days ... skipping multiple weekends and multi day holidays. I have sql table 'tblSchedule_Tasks.' I need to add start date to duration. The calculated enddate needs to skip weekends and a handful of dates in 'tblHoldays.' One wrinkle is that the dateadd function counts day #1 on the date following the Startdate. I need it to start the count on the actual start date. IE, StartDate April 19,2023 with a 2 day duration needs a end date of April 20, 2023. Also the query needs to begin with a startdate validated to a prececessor task. I would like to send you the tables in ssms format. After the queries are written I can take it from there. this is a common business use case in a scheduling program. Are you familiar with working with dates in tsql? i exported the two table using generate script in ssms. For simplicity use scheduleID = 20063 in tblSchedule_Tasks. there are several dummy jobs in the table.