Your contract is valid until the 45 Short Sale Addendum period is up. In your case, based on your offer of January 11th, if it is assumed the sellers also signed and accepted your offer on that date then your addendum expires next week around the 17th or 18th. If the sellers did not sign and date your offer on the 11th, than you will count 45 business days, excluding holidays, to find out when the addendum needs to be extended. The dates on the contract, not the addendum, are the date you ask to close by (page 1 of the contract bottom paragraph), and the date you are giving the seller to respond to the offer (page 8 of the contract top section). When your addendum is expired next week, I would have a new one drafted if you wish to give the bank another period to review your offer. The agent working on your behalf should know that this addendum is set to expire and be in constant contact with the listing agent to understand if approval will be obtained by the lien holders before next week.
I suggest you pull your copy of the contract and review the signature date of the sellers, along with all other dates on the contract and your short sale addendum. Then you should discuss it with your agent.
I hope this assist you.
Best of luck
Michelle Niemczyk, Realtor
Coldwell Banker Residential