Setting Variables in IF statements in SQL Server 2014 - variables

Question

Msg 134, Level 15, State 1, Line 21
The variable name '#AsOfDate' has already been declared. Variable names must be unique within a query batch or stored procedure.
I am getting this error when running a set of IF statements. Ideally I would simply need to toggle my bit to 1 for the quarter I'm interested in and then execute my code. The IF statements would set the dates I need.
I have tried this with IF and ELSE IF, but neither seems to make a difference. Any suggestions on how I can do this would be greatly appreciated. Sadly I can't simply have it pick the quarter I'm in (or the one previous) as these reports may be requested at any time.
-------------------------
-- Choose Quarter --
-------------------------
DECLARE #Q1 BIT = 0
DECLARE #Q2 BIT = 0
DECLARE #Q3 BIT = 0
DECLARE #Q4 BIT = 0
DECLARE #Annual BIT = 0
-------------------------
--Q1
IF #Q1 = '1'
BEGIN
DECLARE #AsOfDate datetime = '2016-03-31';
DECLARE #StartDate datetime = '2016-01-01'
END
--Q2
IF #Q2 = '1'
BEGIN
DECLARE #AsOfDate datetime = '2016-06-30';
DECLARE #StartDate datetime = '2016-04-01'
END
--Q3
IF #Q3 = '1'
BEGIN
DECLARE #AsOfDate datetime = '2016-09-30';
DECLARE #StartDate datetime = '2016-07-01'
END
--Q4
IF #Q4 = '1'
BEGIN
DECLARE #AsOfDate datetime = '2016-12-31';
DECLARE #StartDate datetime = '2016-10-01'
END
-- ANNUAL
IF #Annual = '1'
BEGIN
DECLARE #AsOfDate datetime = '2016-12-31';
DECLARE #StartDate datetime = '2016-01-01'
END
-- Check to ensure a time period is set
IF (#Q1 = 0 AND #Q2 = 0 AND #Q3 = 0 AND #Q4 = 0 AND #ANNUAL = 0)
BEGIN
PRINT 'NO TIME SET'
END
-- Run Code with dates
ELSE
BEGIN
EDIT:
Disregard... actually reading my error and code clearly points to my declares being an issue not the setting of the variable... Solution is to declare the variables outside of my IF statements and SET them in the statement.

Answer 1

I was declaring in each IF statement instead of declaring prior to all the IF statements. Below is the updated version of the code.
DECLARE #ASOfDate DATETIME
DECLARE #StartDate DATETIME
-------------------------
-- Choose Quarter --
-------------------------
DECLARE #Q1 BIT = 0
DECLARE #Q2 BIT = 0
DECLARE #Q3 BIT = 0
DECLARE #Q4 BIT = 0
DECLARE #Anual BIT = 0
-------------------------
--Q1
IF #Q1 = '1'
BEGIN
SET #AsOfDate = '2016-03-31' ; SET #StartDate = '2016-01-01'
END
--Q2
IF #Q2 = '1'
BEGIN
SET #AsOfDate = '2016-06-30' ; SET #StartDate = '2016-04-01'
END
--Q3
IF #Q3 = '1'
BEGIN
SET #AsOfDate = '2016-09-30' ; SET #StartDate = '2016-07-01'
END
--Q4
IF #Q4 = '1'
BEGIN
SET #AsOfDate = '2016-12-31' ; SET #StartDate = '2016-10-01'
END
--ANUAL
IF #Anual = '1'
BEGIN
SET #AsOfDate = '2016-12-31' ; SET #StartDate = '2016-01-01'
END
-- Check to ensure a time period is set
IF (#Q1 = 0 AND #Q2 = 0 AND #Q3 = 0 AND #Q4 = 0 AND #ANUAL = 0)
BEGIN
PRINT 'NO TIME SET'
END
-- Run Code with dates
ELSE
BEGIN
Start of Actual Program using dates shown
END