Dynamic SQL to randomize all datetime columns in a database - sql-server

Question

I'm having trouble figuring out how to use a dynamic SQL Server query to change the datetime fields in my database, called OnlineStore, to be random and in the current year.
It should be noted that this relates to homework. My class is fairly unstructured, so I'm having a hard time knowing where to go from here.
My question is: How can I write a dynamic SQL Server query that may use loops or table variables and takes the 2 datetime columns in my database (Product.LastOrderDate, Orders.OrderDate) and assigns each row a random date in the current year?
This is what I have so far. I'm open to any changes.
Declare #SQL varchar(max) = '
Declare #D1 float = cast(cast(''2017-01-01 00:00:00'' as datetime) as float);
Declare #D2 float = cast(cast(''2017-12-31 23:59:59'' as datetime) as float);

Answer 1

Based on this answer I came up with the following. It randomly adds n seconds to the date 2017-01-01 capped at the number of seconds in 2017.
The first bit is just me generating a table with 50 rows, all 2017-01-01.
You'll want to focus on the parts from update on...
if object_id('tempdb..#test') is not null drop table #test
create table #test (orderDate datetime)
-- add 50 rows to test table
;with x as
(
select 1 as t
union all
select t+1
from x
)
insert into #test
select top 50 '2017-01-01'
from x
option(maxrecursion 50)
--select * from #test
update t
set OrderDate = dateadd(second,ABS(CHECKSUM(NewId())) % datediff(second,'2017-01-01 00:00:00','2017-12-31 23:59:59'),'2017-01-01 00:00:00')
from #test t
select * from #test

Answer 2

Based on this answer: https://stackoverflow.com/a/18408615
This gets you almost all the way there for generating a random date, I capped the days at 28 due to February being February.
select cast('2017-' + CAST(ABS(Checksum(NEWID()) % 12) + 1 AS varchar(2)) + '-' + CAST(ABS(Checksum(NEWID()) % 28) + 1 AS varchar(2)) as date)
You can adapt this to fit your needs.