OPINION
MATTHEWS, Chief Justice.I. INTRODUCTION
Paul Morino filed a motion in superior court to modify a court-approved visitation schedule to allow him an additional overnight visitation per week with his children. He appeals the superior court’s denial of his motion and its award of $1,370 in attorney’s fees to Anne Swayman, the children’s mother. The court denied Morino’s motion without a hearing, ruling that Morino had failed to demonstrate a substantial change in circumstances. It also awarded Swayman her actual attorney’s fees because Morino’s financial resources were greater than Swayman’s and because the court found that his motion was not filed in good faith. We conclude that the court should have held a hearing on Morino’s motion to modify.
II. FACTS AND PROCEEDINGS
Paul Morino and Anne Swayman were divorced on February 12,1996. They have two young children of the marriage.
During the divorce proceedings, Morino and Swayman signed a “Custody, Visitation, and Child Support Agreement.” The agreement provided that Swayman would have sole legal custody of both children. Morino would have two consecutive overnight visitations per week, one three-hour evening visitation mid-week, and summer and holiday visitation. The agreement also provided that beginning on September 1, 1999, the parties would change the visitation to a 50/50 visitation schedule by which they would rotate custody on a weekly basis. The superior court incorporated the agreement into the divorce order, finding that the custody and visitation agreement was in the best interests of the children.
On July 25, 1997, Morino filed a motion to modify visitation to allow him three consecutive overnight visitations per week, and also filed an accompanying motion requesting a hearing. He affied that from September 1996 until late June 1997, he had visitation with the children for three overnights per week pursuant to an informal agreement with Swayman. He also affied that in early June, he had asked Swayman to sign a stipulation to formally change the visitation schedule to reflect the actual visitation. Approxir mately two weeks later, however, Swayman informed him that she would not agree to the modification, and would instead return to the original visitation schedule because she felt the modification was not in the children’s best interests.
Morino argued that the parties’ informal agreement to modify the visitation schedule and the ten-month period when the visitation had actually changed was a substantial change in circumstances and that it was in the best interests of the children to continue with the modified schedule. Swayman opposed the motion, arguing that she had merely tried to accommodate extra visitation, but had not agreed to a formal modification of the visitation order. She argued that Morino had failed to demonstrate a substantial change in circumstances entitling him to an evidentiary hearing and increased visitation would not be in the children’s best interests.
The superior court denied Morino’s motions without a hearing, holding that Morino failed to show a change in circumstances. It also denied Morino’s motion for reconsideration, emphasizing that an informal accommodation in visitation is not a changed circumstance, because such a result would *428discourage custodial parents from allowing favorable deviations from visitation agreements.
Swayman then moved for actual attorney’s fees under AS 25.20.115. The court awarded her $1,370 in actual attorney’s fees, finding that Morino’s relative financial resources were clearly greater than Swayman’s and that Morino’s motion was “vexatious and not in good faith.”
Morino appeals the superior court’s denial of his motion to modify visitation, as well as the award of actual attorney’s fees to Sway-man.
III. DISCUSSION
The Superior Court Should Have Conducted a Hearing Because Morino Alleged Facts Which Could Have Justified a Modification
Reasoning that Morino had failed to demonstrate a substantial change in circumstances, the superior court denied Morino’s motion to modify visitation and denied his motion for a hearing. Morino argues that the court erred in failing to hold an eviden-tiary hearing because the agreement with Swayman to modify the visitation schedule constituted a substantial change in circumstances.
A trial court may modify a visitation award if it determines that “a change in circumstances requires the modification of the award and the modification is in the best interests of the child.” AS 25.20.110(a). The parent moving for modification has the burden of proving a substantial change in circumstances as a threshold matter. See Long v. Long, 816 P.2d 145, 150 (Alaska 1991). The change in circumstances required to modify visitation, though, is not as great as that required for a change in custody. See Carter v. Brodrick, 816 P.2d 202, 204 (Alaska 1991).
A movant who demonstrates a change in circumstances is entitled to an evidentiary hearing to determine whether the modified visitation would be in the child’s best interests. See A.H. v. W.P., 896 P.2d 240, 244 (Alaska 1995). However, a trial court is not required to grant a hearing on a modification motion if it is “plain that the facts alleged in the moving papers, even if established, would not warrant a change.” Deivert v. Oseira, 628 P.2d 575, 578 (Alaska 1981). We recently clarified that the question of whether the moving party has met its burden of demonstrating a change in circumstances so as to be entitled to an evidentiary hearing is a matter of law which we review de novo. See C.R.B. v. C.C., 959 P.2d 375, 378 (Alaska 1998). Thus if a trial court denies a motion to modify visitation without a hearing, “[w]e will affirm if, in our independent judgment, the facts alleged, even if proved, cannot warrant modification, or if the allegations are so general or eonclusory, and so convincingly refuted by competent evidence, as to create no genuine issue of material fact requiring a hearing.” Id.
Because the superior court denied Mori-no’s motion to modify visitation without a hearing, the issue is whether Morino alleged facts that, taken as true, could warrant modification. Morino presented the following in support of his motion. He affied that beginning in September of 1996 Swayman consented to his keeping the children overnight on his mid-week visitation instead of just visiting with them for three hours pursuant to the visitation order. Morino also affied that he subsequently began keeping the children for three consecutive overnights, which replaced his mid-week visitation. Swayman agreed to this change in a letter to Morino. She wrote:
Starting Thursday, February 6, 1997, you’ll have the kiddos from 6:00 p.m. until Sunday at 12:00 p.m. This will give us the same schedule with them without breaking up their routine as much.
Morino argued that it was in the best interest of the children to continue with this schedule, that the children benefitted from the increased time which they spent with him, that the informal agreement to the schedule “demonstrates that such a scheme meets the children’s mental, emotional and social needs,” and that the schedule “is easier on the children because it involves fewer change-overs.” In response to Swayman’s opposition, Morino contended that since the new visitation arrangement had been in place *429since September of 1996 another change would be destabilizing and contrary to the children’s best interests. Further he contended that the children while in his custody were nurtured in a placid and stable home life while, by contrast, in Swayman’s household they were exposed to considerable domestic strife.
Morino argues that the informal agreement and de facto change in the visitation schedule constitute a substantial change in circumstances which entitles him to an evi-dentiary hearing. It is uncontested that the parties informally agreed to modify the visitation schedule. For a ten-month period the informal agreement effectively substituted one additional overnight visitation per week for Morino’s three-hour mid-week visitation. The original visitation schedule had only been in effect for seven months before this change in visitation. Arguably, this substitution could be regarded as a substantial change from the original visitation schedule.
Custodial parents should have the flexibility to experiment with new visitation schedules without fearing that every temporary change could be the basis for modifying visitation. See Gaston v. Gaston, 954 P.2d 572, 574 n. 4 (Alaska 1998) (“Alaska’s family law encourages custodial parents to be flexible in experimenting with visitation schedules, and in most cases parents should feel free to end such experiments if they conclude that they are not working.”). As noted by the superior court, if temporary variations in visitation schedules always constituted a substantial change in circumstances, primary custodians would be discouraged from allowing any favorable deviation from the visitation order.
Nonetheless, at some point, informal or de facto modifications of custodial or visitation arrangements should be formalized. Child support amounts and the number of visitation days allotted to the non-custodial parent are interdependent under Civil Rule 90.3(a) and (b). A premise of the rule is that it is in the best interests of the children that child support amounts bear a prescribed relationship to the time the children spend with each parent. But this can only be accomplished where the decree reflects actual practice. Thus, justice is best served if the child support amount reflects the actual responsibilities and burdens of the parties.1
A de facto change with respect to the custody of a child may be a change of circumstances for the purpose of changing a custodial decree.2 It follows that a de facto change with respect to visitation of a child may be a change of circumstances for the purpose of modifying decreed visitation. Of course, experimental changes lasting only a few months should not qualify as a change in circumstances. Just as surely, de facto changes of a lengthy duration, especially when they are such as to change child support payments when given de jure status, should qualify.
It is a fair question whether the interests of flexibility and experimentation are outweighed by the interest in formalizing a de facto change in this case. We are unable to say as required by Deivert that it is “plain that the facts alleged ... would not warrant a change.” 628 P.2d at 578. Nor can we say, to use the terms of C.R.B., that “the facts alleged ... cannot warrant modification.” 959 P.2d at 378. Instead, we have what appears to be a case where the facts as alleged may or may not warrant modification.3 An exercise of the trial court’s judg*430ment is required. That judgment should be exercised by a fully informed trial court judge after the parties have an opportunity to make their presentations at an evidentiary hearing.
Our disposition in this case concerning the need for a hearing on Morino’s motion for modification requires that the court’s award of attorney’s fees be vacated.
IV. CONCLUSION
For the reasons stated, the orders denying Mormo’s motion to modify and granting an award of attorney’s fees to Swayman are VACATED and this case is REMANDED for further proceedings consistent with this opinion.
FABE, Justice, with whom BRYNER, Justice, joins, dissenting.. See Turinsky v. Long, 910 P.2d 590, 595 (Alaska 1996):
Child support awards should be based on a custody and visitation order. If the parties do not follow the custody order, they should ask the court to enforce the custody order or should move to modify the child support order. Cf. Karpuleon v. Katpuleon, 881 P.2d 318, 320 (Alaska 1994) (burden is on parents to apply promptly for modification when a child changes residency).
. See Boone v. Boone, 960 P.2d 579, 582 (Alaska 1998) (children's change in residence for a period of ten months a material change in circumstances even though former custodial parent argued that it was a "temporary, and voluntary, physical custody arrangement which was never ordered by the court”).
.As previously noted, the substantive requirements for a modification are findings of a substantial change of circumstances and that modification is in the best interest of the children. Supra at 428. Our conclusion that Morino made *430a prima facie case justifying a hearing thus necessarily applies to both requirements. As to the best interest requirement, the showing he made summarized above is sufficient. The duration of the informal modification implies that continuity and stability interests will be advanced. Tire modified schedule brings closer-to-equal contact with each parent and implies improved transitions now, as well as an easier transition to equal contact which will occur as agreed on September 1, 1999. The fact that Swayman agreed to the informal change implies that she thought initially that the changed schedule was at least not in conflict with the children’s best interests.