Marines must request paternity leave within 25 days after the birth of the baby. If deployed, the commander can approve paternity leave within 90 days of deployment and can authorize it outside that time period for extraordinary circumstances.
An injury to a nail may result in the loss of the nail. As long as the nail bed itself wasn't damaged, a lost nail should eventually grow back. Healthy fingernails grow at a rate of about 0.10mm per day, but toenails are slower, growing at only about one half to one third of a fingernail's rate.
Nail detaches partially or fully from the nail bed: known as onycholysis, it can be caused by a trauma or chemicals as well as certain skin conditions; it will not reattach and you'll need to wait for about six months for a fingernail to grow back fully or 18 months for a toenail.