to qualified charities/school orgs.
You still have to pay, but at least you can direct where it goes. Your company may also set up payroll deductions to go directly to the groups instead of you donating and waiting for the return.
Time frame for donations is the same as an IRA contribution - you can still make them for the 2018 tax year.
Total amount for MFJ that you can get the credits for is $4,413. That is up to $150k(ish) Federal AGI (170k gross, give or take)
The credits are:
Public/Charter school - $400
Qualifying Charity - $800
Qualifying Foster Org - $1000
Private School Tuition Orgs - $2213
If you are single, the limits are half that.