You are assuming that your data contains a Date value enclosed in parentheses:
which is not what you say teh table contains.
Either the table contains the date as a string - which is a very bad idea and menas your DB needs to be changed, along with all the software that works with it - or it contains a DATE / DATETIME field in which case it isn't a string at all and won't contain any parentheses.
So start with your DB: look at the table definition and see exactly what and how you are storing your info. If you aren't storing numeric values in numeric fields such as INT, FLOAT, or DECIMAL; and date related into in DATE, DATETIME, or DATETIME2 columns then you need to fix that first.
When you have date related data, you can format your display as you want without the need to faff with strings.