Employer, The Sherwin-Williams Company (Sherwin-Williams), appeals the decision by a hearing examiner finding Cedric Borc-hert’s claim for worker’s compensation benefits and request for hearing were filed timely and awarding partial medical benefits.
We reverse.
ISSUES
The Sherwin-Williams Company, as appellant, presents the following issues:
Was it error to award Appellee (Employee/Claimant below) worker’s compensation benefits?
Under the facts of this case, this issue includes the following sub-issues:
*961Was there a failure by Appellee to timely report his alleged injury and to timely file a report of injury, thereby creating a presumption of denial of benefits which should have precluded the awarding of benefits herein?
Were the claims of Appellee barred by the applicable statute of limitations?
Were the claims of Appellee barred as a result of a failure to timely file a request for healing?
Was there sufficient evidence to support a finding Appellee suffered any injury at work?
Cedric Borehert, as appellee, contends the following:
1. Did Employee/Borchert timely request a hearing upon receiving notice of denial of benefits claimed?
2. When did Employee/Borchert’s injuries become compensable?
a. Did Employee/Borchert timely report his injuries pursuant to W.S. § 27-14-502 after they became compensable?
b. Did Employee/Borchert timely make a claim for benefits pursuant to W.S. § 27-14-503(b) after they became compensable?
3. Is the hearing examiner’s award of partial benefits supported by substantial evidence of record?
FACTS
In April, 1995, Cedric W. Borehert was employed by Sherwin-Williams as assistant manager of the Sherwin-Williams store in Sheridan, Wyoming. His duties included unloading, stacking and distributing freight by hand. On April 22, 1995, while unloading a roll of carpeting weighing approximately 550 to 660 pounds, Borehert experienced aches and pains. In the spring of 1996, he was required to perform more lifting and unloading than usual because of the absence of another employee for nearly two months, and his hip and knees began to bother him. In May, 1996, Borehert resigned his position with Sherwin-Williams for reasons unrelated to the issues presented here.
Borehert had previously separated both shoulders in a fall in 1968 and received treatment by orthopedic surgeon, Edwin Clyde Biddulph, M.D. Surgery to repair a torn rotator cuff and degenerative arthritis in Borchert’s left shoulder was performed on March 10, 1993. Borehert recovered well following the surgery and was able to play softball from 1993 to 1995. Borehert also suffers from conditions of cervical spondylo-sis and arthritis which cause him frequent pain.
Borehert returned to Dr. Biddulph on June 17, 1996, with complaints of pain in both shoulders. Borehert reported to Dr. Bid-dulph he had been doing very well until he unloaded a 600-pound carpet in April of 1995, heard a pop in his left shoulder and had had pain ever since, aggravated by lifting five gallon pails of paint in May. Other than possible arthritis on both shoulders, Dr. Bid-dulph suspected Borehert had retorn his left rotator cuff and experienced a tear in the right rotator cuff as well. An arthrogram was recommended to determine the extent of injury but was not performed at that time.
On June 20, 1996, Borehert submitted a report of occupational injury to his employer, claiming injury to both shoulders and a hernia, resulting from “excessive strain from unloading [a] large roll of carpet, then weekly continued aggravation from unloading-freight by hand.” Borchert’s hernia claim was later withdrawn and is not at issue here. In an attachment to the injury report, Borchert gave the date of injury as on or about April 22, 1995, while unloading a full roll of carpet by hand. The injury report was received by the Division of Workers’ Compensation on July 8, 1996, and on July 12, 1996, the Division issued a Pinal Determination denying Borehert’s claim for benefits because the injury report was not filed within the time allowed by Wyo. Stat. Ann. §§ 27-14-502(a) and 27-14-503(a) and (b). The document required either the employee or employer to file an objection to the final determination by August 7, 1996, or be barred under Wyo. Stat. Ann. § 27-14-601(k), from further administrative or judicial review. A letter from Borehert dated August 2, 1996, objecting to the Division’s determination was date stamped as received by the Division on August 9, 1996.
*962On June 2,1997, a hearing was held before the Office of Administrative Hearings. Borc-hert initially stated, upon receiving the Final Determination, he had only a day or two to respond before the August 7 deadline. Later, he testified he could not recall when he received the document, but thought it was sometime after July 12 and could have been as long as a week before he formulated his response. He testified he wrote the objection on August 2 and sent it via Federal Express on August 5,1996.
Borchert testified he heard his left shoulder pop while unloading the carpet in April, 1995, and had immediate sharp stabbing pain in four areas. In a deposition given before the administrative hearing, Borchert apparently indicated he experienced no pain when moving the carpet and heard no unusual noises. When asked whether he thought he had torn his rotator cuff in April, 1995, Borc-hert stated he didn’t know, “but something happened.” He further testified he thought he had pulled some muscles and was unaware of any specific injuries to his shoulder at that time. In later testimony, Borchert could not recall hearing a pop in his shoulder, then stated it was probably his right, not left, shoulder that popped.
Dr. Biddulph opined, based on the history given him by Borchert, any possible injury to Borchert’s left shoulder probably happened in April, 1995, when Borchert was lifting and heard his shoulder pop, aggravated by subsequent lifting. When asked whether an injury would have been readily apparent to Borc-hert in April, 1995, Dr. Biddulph stated, “The way he described it to me, he was sure aware that something happened at that point.” Dr. Biddulph acknowledged his opinions regarding causation of Borchert’s injuries “relied very heavily on the truthfulness of the history” reported by Borchert.
An intra-office memo written by Sherwin-Williams’ store manager on July 17, 1996, indicated the store manager had no knowledge of a work-related claim for injuries by Borchert until June 17, 1996; that Borchert had complained of his shoulders and hands jiurting from the time he began work at the Sheridan store in April, 1995; and that at no time did Borchert inform the store manager his pain was work related. The store manager testified when Borchert did complain about pain, he related the pain to his arthritis.
The hearing examiner concluded Borc-hert’s request for hearing was timely filed because of conflicting testimony and evidence regarding dates the Final Determination was written, mailed to, and received by Borchert. The hearing examiner determined Borchert’s injury was not readily apparent on April 22, 1995, but occurred over a substantial period of time and thus his claim was timely filed within one year after the preliminary diagnosis was made known to him on June 17,1996. Borchert was awarded partial medical benefits. Sherwin-Williams’ appeal of the hearing examiner’s decision to the district court was certified to this Court, pursuant to W.R.A.P. 12.09(b).
DISCUSSION
Standard of Review
Sherwin-Williams argues Borchert suffered injury in April, 1995, rendering his July 8, 1996, claim for benefits time-barred as beyond the one year statute of limitations. It further contends the hearing examiner’s determination of Borchert’s request for hearing as timely filed is not supported by substantial evidence.
Wyo. Stat. Ann. § 16-3-114(e) (LEXIS 1999) provides, in pertinent part, this Court’s standard for review of agency decisions:
(c) ... the court shall review the whole record or those parts of it cited by a party and due account shall be taken of the rule of prejudicial error. The reviewing court shall:
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(ii) Hold unlawful and set aside agency action, findings and conclusions found to be:
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(E) Unsupported by substantial evidence in a case reviewed on the record of an agency hearing provided by statute.
We must examine the entire record and consider conflicting and contradictory ev-*963idenee to determine whether, in light of all the evidence before it, the hearing examiner could have reasonably concluded as it has in this case. Carrilo v. State of Wyoming ex rel. Wyo. Workers’ Safety and Comp. Div., 987 P.2d 690, 693 (Wyo.1999). Substantial evidence is “relevant evidence that a reasonable mind can accept as adequate to support an agency’s conclusions.” Sheneman v. Div. of Workers’ Safety and Comp. Internal Hearing Unit, 956 P.2d 344, 348 (Wyo.1998) (citing Casper Oil Co. v. Evenson, 888 P.2d 221, 224 (Wyo.1995)). This Court will not substitute its judgment for that of an agency and defers to an agency’s findings of basic fact provided there is substantial evidence supporting such findings. Matter of Zielinske, 959 P.2d 706, 709 (Wyo.1998). However, if an agency’s decision is clearly contrary to the overwhelming weight of the evidence presented in the record, we will overturn the decision. Nissen v. Cheyenne Frontier Days, 983 P.2d 722, 724-25 (Wyo.1999).
The burden of proof for worker’s compensation benefits is on the claimant to prove all essential elements of his claim by a preponderance of the evidence. Carrillo, 987 P.2d at 692. In other words, the claimant “has the burden of following procedures and rules contained within the Workers’ Compensation Act before he is entitled to worker’s compensation benefits.” Pittman v. State ex rel. Wyo. Workers’ Comp. Div., 917 P.2d 614, 617 (Wyo.1996). “To prove by a preponderance of the evidence, the claimant must bring forth ‘proof which leads the trier of fact to find that the existence of the contested fact is more probable than its non-existence.’ ” Carrillo, 987 P.2d at 692 (citing Thornberg v. State, ex rel. Workers’ Comp. Div., 913 P.2d 863, 866 (Wyo.1996) quoting Scherling v. Kilgore, 599 P.2d 1352, 1359 (Wyo.1979)).
Timeliness of Claim
We first address Sherwin-Williams’ contention of eiror in the hearing examiner’s conclusion that Borchert’s injury occurred over a substantial period of time, resulting in his claim being timely filed within the statute of limitation. The Wyoming Workers’ Compensation Act in effect at the time of Borc-hert’s injury provides, in pertinent part, as follows:
§ 27-14-502. Employee’s report of accident to employer and clerk of court; presumption raised by failure to file report; release of information.
(a) As soon as is practical but not later than seventy-two (72) hours after the general nature of the injury became apparent, an injured employee shall report the occurrence and general nature of the accident to the employer and within ten (10) days after the injury became apparent, file the report in the office of the clerk of court of the county in which the accident occurred. Within one (1) working day after receipt of the employee’s report, the clerk shall transmit a copy of the report to the division and the employer....
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(c) Failure of the injured employee, any dependent or personal representative to report the accident to the employer and to file the report with the clerk of court in accordance with subsection (a) of this section is a presumption that the claim shall be denied. The presumption may be rebutted if the employee establishes by clear and convincing evidence a lack of prejudice to the employer or division in investigating the accident and in monitoring medical treatment.
Wyo. Stat. Ann. § 27-14-502 (Michie 1991 Repl.Vol.).
§ 27-14-503. Statute of limitations; transfer of claim.
(a) A payment for benefits involving an injury which is the result of a single brief occurrence rather than occurring over a substantial period of time shall not be made unless in addition to the proper and timely filing of the reports of the accident, an application or claim for benefits is filed within one (1) year after the date of the accident occurred or for injuries not readily apparent, within one (1) year after discovery of the injury by the employee. The report of accident is not a claim for benefits.
(b) The right of compensation for an injury which occurs over a substantial period of time is barred unless a claim for *964benefits is filed within one (1) year after a diagnosis of injury is first communicated to the employee, or within three (3) years from the date of last injurious workplace exposure to the condition causing the injury, whichever occurs last,....
Wyo. Stat. Ann. § 27-14-503 (Michie 1996 Cum.Supp.)
When the discovery of a compensable injury and causal relationship between the injury and employment is at issue, we have previously noted “a claimant is required to use due diligence in pursuing his claim.” Pittman, 917 P.2d at 617 (citing Olheiser v. State ex rel. Worker’s Comp. Div., 866 P.2d 768, 773 (Wyo.1994)). We have recognized due diligence as:
Such a measure of prudence, activity, or assiduity, as is properly to be expected from, and ordinarily exercised by, a reasonable and prudent [person] under the particular circumstances; not measured by any absolute standard, but depending on the relative facts of the special case.
Id. at 618 (quoting Black’s Law Dictionary (6th ed.1990)).
The question becomes, when would a reasonable person in Borchert’s circumstances have understood the full extent and nature of the injury and that the injury was related to his employment? Id. at 617. On the injury report and accompanying attachment completed by Borchert, he attributed the cause of his shoulder injuries to unloading the carpet in April, 1995. He reported the same to Dr. Biddulph at the time of his examination in June, 1996, with enough accentuation to cause Dr. Biddulph to state he felt Borchert had been “sure something happened at that point.” Only under oath does Borchert’s testimony become equivocal. His testimony ranged from hearing a pop in his left shoulder and experiencing pain, to hearing no pop and experiencing no pain, to believing the pop was from his right shoulder.
We do not find substantial evidence to support the hearing examiner’s finding that Borchert’s injury was not readily apparent on April 22, 1995. By his own report, Borc-hert attributes his shoulder injuries to the incident in April, 1995. We have stated, “[I]f a person fails to exercise due diligence in the pursuit of his claim, then he has failed to act as a reasonable person under the circumstances and his claim will be barred if the one-year time limit has expired.” Pittman, 917 P.2d at 618 (citing Olheiser, 866 P.2d at 773). We do not find substantial evidence to support the conclusion Borchert’s injury was not apparent until June, 1996. Borchert’s report of injury on July 8, 1996, was time barred under Wyo. Stat. Ann. § 27-14-503(a) as beyond the one year time period provided by law.
Borchert failed to notify his employer within seventy-two hours after the general nature of his injury became apparent as required by Wyo. Stat. Ann. § 27-14-502(a). To overcome a presumption of denial of his claim for failure to timely report to his employer, it becomes Borchert’s burden to show, by clear and convincing evidence, a lack of prejudice to his employer or the Division in investigating the injury and monitoring medical treatment. Wyo. Stat. Ann. § 27-14-502(c) (Michie 1991 Repl.Vol.) “Without such evidence in the record, an employee cannot rebut the presumption of prejudice.” Nissen, 983 P.2d at 725 (citing Clark v. State ex rel. Workers’ Safety Comp. Div., 968 P.2d 436, 439 (Wyo.1998)). Borchert failed to submit any evidence showing Sherwin-Williams and the Division were not prejudiced by a lack of opportunity to investigate and monitor Borchert’s injury. We note Borchert continued to work for Sher-win-Williams, unloading freight and moving five gallon pails from the time his injury became apparent in April, 1995, until he resigned in May, 1996. With no notice of the injury, Sherwin-Williams had no opportunity to modify his work duties and minimize his lifting activities. Likewise, the Division was afforded no opportunity to investigate the injury. As such, Borchert has failed to rebut the statutory presumption that his claim should be denied. Matter of Zielinske, 959 P.2d at 711.
Timeliness of request for hearing
Finally, we address the timeliness of Borc-hert’s objection to the Division’s denial of *965benefits and request for hearing. The July 12, 1996, Pinal Determination required Borc-hert to respond in writing by August 7,1996. The Division received Borchert’s written response on August 9, 1996, two days beyond the deadline. In review of the record and Borehert’s testimony on this point, we again find his statements to be equivocal. He alternately testified he received the document with only a day or two to respond, could not recall when he received it or had as long as a week to respond. The Wyoming Workers’ Compensation Act in effect at the time of the injury clearly states, in pertinent part, as follows:
(vi) If timely written request for hearing is not filed, the final determination by the division pursuant to this subsection shall not be subject to further administrative or judicial review.
Wyo. Stat. Ann. § 27-14-601(k)(vi) (Michie 1996 Cum.Supp.).
We find the Division’s Pinal Determination provided Borchert the required notice of a right to a hearing before a hearing examiner and correctly calculated the deadline for receipt of his response by the Division in order to secure this right. Consequently, we find the hearing examiner’s determination of Bor chert’s request for hearing as timely filed to be unsupported by substantial evidence. Sheneman, 956 P.2d at 352.
CONCLUSION
Borchert’s injury was apparent to him on April 22, 1995, at the time he unloaded the carpet for Sherwin-Williams. Borchert failed to file his claim for worker’s compensation benefits within the one year limitation provided by statute and has not shown his failure to do so resulted in a lack of prejudice to either his employer or the Division. Borc-hert’s request for hearing on the Division’s initial denial of benefits was not received within the timeline correctly calculated and required by the Division, and as such, he is not entitled to administrative or judicial review of his claim on the merits. The hearing examiner’s decision awarding medical benefits is not supported by substantial evidence, is contrary to law, and is reversed.