38 CFR § 21.5831 - Commencing date of subsistence allowance.
The commencing date of an award or increased award of subsistence allowance will be determined by this section
(a) Entrance or reentrance. Latest of the following dates:
(1) Date certified by school or establishment under paragraph (b) or (c) of this section.
(2) Date 1 year before the date of receipt of the application or enrollment certification.
(3) Date of reopened application under paragraph (d) of this section.
(4) In the case of a spouse, surviving spouse, or dependent child, the date that transfer of eligibility and entitlement to the individual was effective.
(b) Certification by the school-course leads to a standard college degree. The date of registration or the date of reporting where the student is required by the school's published standard to report in advance of registration, but not later than the date the individual first reports for classes.
(c) Certification by school or establishment-course does not lead to a standard college degree. First date of class attendance.
(d) Reopened application after abandonment. Date of receipt in VA of application or enrollment certification, whichever is later.
(e) Increase due to increased training time. The date the school certifies the individual became a full-time student.
(f) Liberalizing laws and administrative issues. In accordance with facts found, but not earlier than the effective date of the act or administrative issue.
(g) Correction of military records. When a veteran becomes eligible following correction or modification of military records under 10 U.S.C. 1552 or change, correction or modification of a discharge or dismissal under 10 U.S.C. 1553; or other competent military authority, the commencing date of subsistence allowance will be in accordance with the facts found, but not earlier than the date the change, correction or modification was made by the service department.