It looks like you are editing the standard base calendar and this calendar is associated with both the teams.
In Project, base calendar is a template that has the common working time and holidays. You can create a base calendar for each team. Then, associate the respective base calendar to the team members.
First, create a base calendar for each team – if project 2003/2007, choose Tools, Change working time, if project 2010/2013, choose Project tab, change working time. Change the working time using work weeks.
Next, change the view to resource sheet. Add the team member details. Double click the resource, and select change working time. Now, select the appropriate base calendar from which the working time should be inherited to resource calendar.
So, if you change the base calendar working time then it will be applied to all team members associates with that base calendar.