Marvin Steinbach and his wife, Joyce Gustafson, lived together for only a few weeks after their marriage. During their separation, Gustafson gave birth to a child and entered her surname on the *181child's birth certificate, pursuant to sec. 69.14(l)(f)l.b, Stats., which allows the parent with either legal or "actual" custody of a child conceived during a valid marriage, but born after divorce or separation, to select the name to be entered on the certificate. In the judgment of divorce, the trial court directed that the child's name be changed to Steinbach but later reopened the judgment at Gustafson's request and vacated the language requiring the name change.
Steinbach appeals from the order reopening the judgment and from an order denying his motion for reconsideration. He argues: (1) that the trial court erred in concluding that Gustafson's motion to reopen the judgment was timely filed; (2) that the court exceeded its discretion in deciding to reopen; and (3) that sec. 69.14(l)(f)l.b, Stats., is a gender-specific statute favoring women and thus violates his right to equal protection of the law. We see no error in the court's order reopening the judgment, and we reject Stein-bach's claim that sec. 69.14(l)(f)l.b is unconstitutional.
The facts are undisputed. Steinbach and Gustaf-son were married in 1989 and lived together for only a few weeks before they separated and Steinbach commenced this action for divorce. As indicated, during their brief time together, Gustafson became pregnant. Initially at least, Steinbach declined to acknowledge that he was the father of the unborn child, and a stipulated temporary order was entered providing, among other things, that "[c]ustody and physical placement of the minor child will remain open until the child is born, and until further hearing of the court." The child was bom on February 23, 1990, and Gustafson listed the child's surname as "Gustafson" on the birth certificate.
Meanwhile, the divorce proceedings continued. At Steinbach's request, the trial court appointed a guard*182ian ad litem for the child on May 20,1990, and ordered blood tests to determine paternity. On July 20, the family court commissioner entered a second temporary order stating, again pursuant to stipulation, that, pending further order, the parties would have "joint legal custody" of the child and that Gustafson "shall be the [child’s] primary caretaker and her residence the primary home of the child."
The blood tests eventually revealed Steinbach to be the child's father and the case went to trial on January 18, 1991. The parties stipulated to joint custody, contesting only the child's physical placement. Stein-bach also sought to have the surname on the child's birth certificate changed to his. The trial court rendered a decision from the bench ordering joint legal custody pursuant to the stipulation and directing physical placement of the child with Gustafson. Steinbach was granted visitation rights and was ordered to pay child support. The trial court also granted his request to have the child's name changed to Steinbach.
Several months later, on May 3, 1991, the trial court signed and entered written findings of fact, conclusions of law and judgment implementing its earlier oral decision. The court found that the child was a child of the marriage and that its name "shall be changed from . . . Gu[s]tafson to . . . Steinbach" and directed Steinbach to make the necessary arrangements.
Then, nearly a year later, on April 20, 1992, Gus-tafson moved to reopen and amend the judgment to delete the provision ordering the child's name to be changed. At about the same time, Steinbach filed a motion seeking to have Gustafson found in contempt for refusing to sign the necessary papers for the name change.
*183At a hearing on the motions, the trial court granted Gustafson's motion to reopen and, concluding that it lacked authority to order the child's name to be changed, vacated that portion of the earlier judgment.1 Steinbach moved for reconsideration, which the court denied. He appeals both orders.
I. Timeliness of the Motion To Reopen
Steinbach argues first that he was given insufficient notice of the hearing on Gustafson's motion to reopen the divorce judgment, in that it was served on him only six days prior to the hearing, rather than eight days in advance, as prescribed by statute, and he claims that the trial court erred in refusing to dismiss it.2 The trial court, having received a trial brief on the name-change issue from Steinbach and noting that his counsel "appear[ed] . .. prepared" to proceed, declined to dismiss the motion but instead rescheduled the hearing to a later date to allow additional time for Steinbach to prepare his case. As a result, it is difficult to see how Steinbach could have been prejudiced by service of the motion six, rather than eight, days prior to the hearing; and he does not argue that he was.
Nor does he contend that Gustafson's motion was filed later than "one year after the judgment was *184entered" within the meaning of sec. 806.07(2), Stats.3 His complaint seems to be that because the judgment was not entered until several weeks after the trial, the motion should be considered untimely because the trial took place more than one year prior to Gustafson's motion. The statute, however, runs from the entry of judgment, not from the date of trial. Steinbach has offered no authority to the contrary and has not persuaded us that the trial court erred in declining to dismiss Gustafson's motion as untimely.
II. Erroneous Exercise of Discretion
As we are able to discern it, Steinbach's argument appears to be that the trial court exceeded its discretion in reopening the judgment because, in doing so, it considered only its legal authority to order the name change and did not consider "whether . . . the best interests of the child would be served by reopening the judgment." In so arguing, he relies on Johnson v. Johnson, 157 Wis. 2d 490, 500, 460 N.W.2d 166, 170 (Ct. App. 1990), where we said that, in considering whether to reopen the custody provisions of a divorce judgment on grounds of misrepresentation under the "catch-all" provisions of sec. 806.07(l)(h), Stats.,4 the child's interest would be "highly relevant" to the inquiry.
*185This, of course, is not a custody proceeding where the child's interests are made paramount by statute. See, e.g., sec. 767.24(5), Stats. It also appears that the parties had been disputing Gustafson's right to give her name to the child for several weeks prior to the motion to reopen. As we have noted above, Steinbach had filed a contempt motion on the same subject several days before the first hearing on Gustafson's motion. At the initial hearing, the trial court expressed doubts as to its authority to order the name change in the first place and, considering the issue to be one of law, recessed the hearing to allow Steinbach time to prepare a response rather than dismissing the proceeding only to put Gustafson through the expense of refiling and re-serving her motion. We note, too, that Steinbach filed a brief with the court at the first hearing addressing the merits of the court's authority to order the change.
The limited scope of our review of discretionary rulings is well settled. Generally, "[w]e will not reverse a discretionary determination by the trial court if the record shows that discretion was in fact exercised and we can perceive a reasonable basis for the court's decision." Prahl v. Brosamle, 142 Wis. 2d 658, 667, 420 N.W.2d 372, 376 (Ct. App. 1987). Indeed, "[b]ecause the exercise of discretion is so essential to the trial court's functioning, we generally look for reasons to sustain discretionary determinations." Schneller v. St. Mary's Hosp., 155 Wis. 2d 365, 374, 455 N.W.2d 250, 254 (Ct. App. 1990), aff'd, 162 Wis. 2d 296, 470 N.W.2d 873 (1991).
To determine whether the trial court properly exercised its discretion in a particular matter, we look first to the court's on-the-record explanation of the rea*186sons underlying its decision. And if that explanation indicates that the court looked to and "considered the facts of the case and reasoned its way to a conclusion that is (a) one a reasonable judge could reach and (b) consistent with applicable law, we will affirm the decision even if it is not one with which we ourselves would agree." Burkes v. Hales, 165 Wis. 2d 585, 590, 478 N.W.2d 37, 39 (Ct. App. 1991) (footnote omitted).
The trial court considered Steinbach's arguments and explained its reasons for granting a continuance rather than dismissing the proceeding. It expressed its doubts as to the existence of legal authority to order the name-change in the divorce judgment, and it adjourned the hearing to a later date in order to give Steinbach additional time to prepare to argue that issue. That is an appropriate, adequately explained exercise of discretion, and we will not disturb the court's ruling.
III. Constitutionality of Sec. 69.14(l)(f)l.b, Stats.
Steinbach next argues that the statute under which Gustafson named the child, sec. 69.14(l)(f)l.b, Stats., violates the equal protection provisions of the fourteenth amendment to the United States Constitution. The statute provides that:
If the mother of a [child] ... is married to the father of the [child] at any time from ... conception to . . . birth . . . and the mother is separated or divorced from the father... at the time of birth, the given name and surname which the parent... with actual custody enters ... on the birth certificate shall be the [child's] given name and surname . . ., except that if a court has granted legal custody of the [child], the given name and surname which the person with legal custody enters ... on the birth *187certificate shall be the given name and surname [of the child]. Id.
Steinbach points to another requirement in the statute that the birth certificate must be filed within five days of birth5 and argues that because "in ninety-nine out of one hundred cases the mother having just given birth" will be the parent in custody of the child, she "will be the one naming [it]." He contends that this gives a "preference to the female sex to name the child" and thus denies a separated or divorced father equal protection of the law. We do not see sec. 69.14(l)(f)l.b, Stats., as creating a gender preference for the mother.
Initially, we are guided in our inquiry by the basic principle that statutes are presumed to be constitutional, and that one challenging the validity of a law must prove unconstitutionality beyond a reasonable doubt. Employers Health Ins. Co. v. Tesmer, 161 Wis. 2d 733, 737, 469 N.W.2d 203, 205 (Ct. App. 1991). It is a "heavy" burden, id., for we will sustain a statute against such a challenge "if there is any reasonable basis for the exercise of legislative power." State v. Hermann, 164 Wis. 2d 269, 281, 474 N.W.2d 906, 911 (Ct. App. 1991). Thus:
It is insufficient to merely establish doubt as to an act's constitutionality nor is it sufficient to establish the act is probably unconstitutional. This court indulges every presumption [of constitutionality] and will sustain the law if at all possible. If any doubt exists as to a law's unconstitutionality, it will *188be resolved in favor of its validity. Quinn v. Town of Dodgeville, 122 Wis. 2d 570, 577, 364 N.W.2d 149, 154 (1985).
We recognize that statutes in other states mandating giving the child the father's name, or giving the father the sole right to name the child, have been — quite appropriately, we think — struck down. See O'Brien v. Tilson, 523 F. Supp. 494, 496 (E.D. N.C., 1981) (North Carolina statute requiring children born of married parents to be given father's surname held unconstitutional); Schiffman v. Schiffman, 620 P.2d 579, 583 (Cal. 1980) (California statute giving father sole right to name child held unconstitutional).
We see no such defect in sec. 69.14(l)(f)l.b, Stats. We belieVe the statute is gender-neutral. It does not state or create a sexual preference; it simply provides that in instances where the parents were married at the time of conception, but were divorced or separated at the time of birth, the parent with legal custody at the time the certificate is prepared may enter the name or, if legal custody has not been determined, the parent with "actual custody" may do so.
And while it may be true that in many, if not most, instances the mother will be the person with "actual" physical custody of the child in the days following its birth, "the Fourteenth Amendment guarantees equal laws, not equal results." Personnel Adm'r of Massachusetts v. Feeny, 442 U.S. 256, 273 (1979). There appears to be no impediment in Wisconsin to a father seeking and obtaining either sole or joint legal custody of a child prior to birth. Wisconsin law provides for actions to determine custody, and since the statute granting that right, sec. 767.02(1)(e), Stats., contains no indication that it would not apply to determining custody of *189yet-to-be-born children, the person with legal custody of the child at birth could be either parent or both. Thus, should a father in a situation such as this desire the right to name the child, or exercise other rights of legal custody, he could seek a custody determination prior to the child's birth. And, were he to be successful, sec. 69.14(l)(f)l.b, Stats., would empower him to enter the child's name on the certificate.6 We thus reject Steinbach's argument that the statute states an unconstitutional preference for the mother.
By the Court. — Orders affirmed.
At one point during the hearing, the trial court remarked that "it would be in the best interest of the child to have the name of Steinbach." The subsequent written order implementing its decision, however, contains no such reference.
Because of intervening holidays, secs. 801.15(4) and (5), Stats., would add three days to the normal five-day requirement for service of motion papers.
Section 806.07(2), Stats., states in pertinent part that a motion to reopen a judgment "shall be made ... not more than one year after the judgment was entered." Section 806.06(1)(b), Stats., provides that a judgment is "entered when it is filed in the office of the clerk of court."
After listing several specific grounds for reopening a judgment, sec. 806.07(l)(h), Stats., states that, "upon such terms as are just, the court may relieve a party... from a judgment... for ... [a]ny other reasons justifying relief from the operation of the judgment."
Section 69.14(l)(a), Stats., states that "a certificate of birth for every birth which occurs in this state shall be filed ... within 5 days after the birth and shall be registered under this subchapter."
In this case, rather than seek such a determination, Stein-bach agreed to entry of the first temporary order providing that any custody order would be postponed until after the child's birth. Indeed, as we have noted above, it appears that at the time of the child's birth, he was not prepared to concede that he was the child's father.