I has this happen to me, you need to find out thru your company what documents they need to stop the garnishment. In my case all my wages garnished were returned once I provided that paperwork . Good Luck
In order to file, you need to locate a clerk or judge willing to accept your documents on a weekend, an arrangement that usually requires a few days notice and a little clout.
However some of federal bankruptcy courts now accept electronic filings.
Good luck keeping your money.
The automatic stay goes into affect immediately however the 30th maybe too soon to stop garnishment. If it is Government, it could be stopped and if private business maybe longer. You will eventually see it stopped at some point. Note: Given as informational only.
Tomorrow after filing, I would download a copy of the notice of bankruptcy filing and email it to your company's HR department and the creditor garnishing your wages. Then if you had to, you could easily argue that both were made aware of the filing before a check could have gone out the door.
In the event a check was already mailed, I believe you should receive it back, perhaps after discharge. Your attorney can discuss other strategies such as scheduling your pay/cash, if it is required.