I know this is going to look like a really long post so just hang with me.
Checking Account #1
12/01/2007 Beginning Balance = $10,000
Assuming no other checks or deposits were posted to this account and since you didn't record the check that you wrote out of this account and deposited into another account then the balance at 12/31/2007 = $10,000
Checking Account #2
12/01/2007 Beginning Balance = $10,000
You deposited a check for $5,000 into Checking Account #2 on 12/31/07
Assuming there were no other checks or deposits into this account then your reconciled balance on 12/31/2007 is $15,000.
Because you didn't record the withdrawal (check) from #1 then Cash #1 is overstated by $5,000.
Here are the journal entries shown in the order of the problem:
12/31/2007
dr Cash #2 $5,000
cr Cash Transfers $5,000
To deposit the check from Cash #1
01/05/2008
dr Cash Transfers $5,000
cr Cash #1 $5,000
To write the check deposited into Cash #2 on 12/31/07
Bank Recon at 12/31/07 as shown in the problem:
Cash #1 Beginning Balance = $10,000
Cash #1 Ending Balance = $10,000
Cash #2 Beginning Balance = $10,000
Deposit in Transit = $5,000
Cash #2 Ending Balance = $15,000
Here are the journal entries shown in the correct order:
12/31/2007
dr Cash Transfers $5,000
cr Cash #1 $5,000
To write the check from Cash #1
dr Cash #2 $5,000
cr Cash Transfers $5,000
To deposit the check from Cash #1 into Cash #2
Cash Transfers should ALWAYS be zero.
Bank Recon as it should have been:
Cash #1 Beginning Balance = $10,000
Outstanding Check = ($5,000)
Cash #1 Ending Balance = $5,000
Cash #2 Beginning Balance = $10,000
Outstanding Deposit = $5,000
Cash #2 Ending Balance = $15,000
It matters that cash was received in year 1 and disbursed in year 2 because you overstate your assets on the balance sheet by doing this. The main reason they give you the dates the check and deposit cleared the bank is to confuse you. You only really need those dates if the disbursement and receipt are posted correctly but the check hasn't cleared the bank. For example: Let say you wrote a check for $100 from account #1 and made a deposit into account #2 for $100 on 12/30/11. The deposit could post in account #2 on 12/31/11 but the check may not show up on the banks books for account #1 until 1/2/12. In that case when you look at the Bank Recon for account #1 on 12/31/11, you would see an outstanding check for $100.
I know this is long but I hope I explained it so that you could understand it.