20 C.F.R. § 618.615
(a) One training program per certification.
(b) Full-time or part-time training. A State may approve a training program on a full-time or part-time basis. A trade-affected worker's approved training program may consist of either part-time or full-time training, or a combination of both. A worker may switch from part-time to full-time training or from full-time to part-time training during the period of the worker's participation in the program. The training program must be amended each time this occurs, in accordance with § 618.665.
(2) Part-time.
(d) Length of training. The State, in determining whether to approve a training program, must determine the appropriateness of the length of training, as follows:
(3) Duration.
(4) Exception for certain workers who perform a period of duty in the Uniformed Services. A member of one of the reserve components of the U.S. Armed Forces who serves a period of duty will have the period for training, under paragraph (a)(3) of this section, suspended upon being called up to duty, provided the requirements specified in paragraphs (a)(4)(i) through (iii) of this section are met. Any such reserve component member may either resume training upon discharge from active service for the training period that remained at the time the reservist left the training program to report for active duty, or be allowed to repeat portions of the training if doing so is necessary for completion of the approved training program or, where appropriate, begin a new approved training program. Where the reservist repeats a training program or begins a new training program, the reservist will be entitled to a new 130-week period to complete approved training. To be eligible to resume, repeat, or begin a new approved training program, the reservist must meet the following requirements:
(iii) For purposes of the exception in this paragraph (d)(4), period of duty means: