In part because doing so would change when the team could backdate a DL assignment.
From the stltoday.com
On to your question about whether the employer has to backdate their contributions.
From the nzherald.co.nz
If he isn't ready by Friday, the Mets would put him on the DL and backdate the move.
From the buffalonews.com
C2C alleges Mr Leigh tried to backdate this transaction to November 3, 2008.
From the smh.com.au
Nicholas is accused of conspiring to backdate $2.2 billion in employee stock options.
From the sacbee.com
Lawmakers could backdate transfers to the beginning of the legislative year in December.
From the sacbee.com
Authorities accuse them of conspiring to backdate employee stock options.
From the sacbee.com
He even went so far as to say backdate the total amount owed to him.
From the express.co.uk
Theoretically, the Yankees could put Pettitte on the 15-day disabled list and backdate his assignment.
From the nytimes.com
More examples
Make effective from an earlier date; "The increase in tax was backdated to January"
Options backdating is the practice of issuing options contracts on a later date than which the options have listed. ...
To give or assign a date to a document that is earlier than the current date
(Backdating) Making the effective date of a policy earlier than the date of application. Backdating is often used to make the age of the applicant lower than it actually was at the time of application so that he/she can get a lower premium. State laws often set limits to this.
Backdating is used in relation to funds that offer declining proportional sales charges of larger purchases. This permits investors to count previous purchases of the fund's shares in qualifying for reduced loads or sales charges on subsequent purchases.
(Backdating) Predating a document or instrument prior to the date it was actually drawn. The negotiability of an instrument is not affected by the fact that it is backdated.
(Backdating (or Back-starting)) Starting new subscriptions with back issues rather than with the current issue. This can be requested by the subscriber or could be initiated by the publisher to increase circulation volumes within an ABC audit period
(Back-dating) when insurance cover begins before the date the cover is issued
(Backdating) Receiving payments from the past. If you wait a while to file your claim, you will not receive any backdated checks to make up for the gap between the date you filed and the date you were unemployed. ...