Query is executing but giving error when using with shell scripting

Please suggest what is giving error here
when I execute from psql prompt, I get the result, when I try to automate
using a shell script, the query is not working

# `/usr/bin/psql -U postgres -d coba1 -c "select name from users where
"Date" > current_date - 30;"`
ERROR: column "Date" does not exist
LINE 1: select name from users where Date >current_...

========

works below

^
sudo -u postgres psql

psql (9.4.5)
Type "help" for help.

postgres=# \connect coba1
You are now connected to database "coba1" as user "postgres".
coba1=# select name from users where "Date" >current_date - 30;
name
---------------------
coba11
testCoba11

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