       DISTRICT COURT OF APPEAL OF THE STATE OF FLORIDA
                             FOURTH DISTRICT

                       KARVOILL K. WILLIAMS,
                            Appellant,

                                    v.

        ROOSDELE BOSSICOT a/k/a ROOSEDELE BOSSICOT,
                         Appellee.

                              No. 4D20-524

                              [July 8, 2020]

  Appeal from the Circuit Court for the Fifteenth Judicial Circuit, Palm
Beach County; Scott I. Suskauer, Judge; L.T. Case No. 50-2019-DR-
000385-XXXX-NB.

   Tasha M. Simmonds of The Law Firm of Ayo & Iken, PLC,
Fort Lauderdale, for appellant.

   Craig A. Boudreau of Boudreau Law, West Palm Beach, for appellee.

DAMOORGIAN, J.

   Karvoill K. Williams (“Father”) appeals the trial court’s final judgment
of determination of paternity, time-sharing, and child support. After
considering the several issues raised by Father, we hold that the trial
court’s child support award failed to take into account the substantial
amount of time-sharing awarded to Father. We affirm without further
comment the other issues raised by Father.

   Father and Roosdele Bossicot (“Mother”) were involved in a romantic
relationship which produced one child. Mother resides in Florida with the
child, and Father resides in North Carolina. Mother filed a petition to
determine paternity, a time-sharing schedule, and an award of child
support.

   Following a non-jury trial, the trial court entered a written final
judgment of determination of paternity. The final judgment also contained
a parenting plan which established the following time-sharing schedule for
Father:
      a. Thanksgiving. In odd-numbered years, the entire
         Thanksgiving Break commencing from the end of school
         until 6:00 p.m. the night before the resumption of school.

      b. Christmas. In even-numbered years, Winter Break from
         the last day of school until two days before the
         recommencement of school.

      c. Summer. In even-numbered years from the Sunday after
         the end of school until 6:00 p.m. ten days before the start
         of the school year.

      d. Spring Break. Every from the end of school until 6:00 p.m.
         on the day before the resumption of school.

      e. Floating weekends. Father shall be entitled to weekend
         timesharing from the end of school until 4:00 p.m.
         (6:00 p.m. if Father is exercising timesharing in South
         Florida or returning child to Mother’s residence) the night
         before the resumption of school in the months of February,
         April, September, November in even-numbered years, and
         December in odd-numbered years.            November and
         December weekend timesharing cannot interfere with
         Thanksgiving or Winter Break.

   Based on the amount of time-sharing awarded to Father, the trial court
made a finding that the child spends a substantial amount of time with
both parents: 23% with Father and 77% with Mother. Finally, Father was
ordered to pay child support in the amount of $750 per month.

   Father argues that the trial court’s award of child support fails to take
into account its own finding that Father has a substantial amount of time-
sharing with the child. Accordingly, the child support amount should be
reduced because Father will be caring for the child’s needs when the child
is with him. We agree.

    “A child support determination is within the sound discretion of the
trial court, subject to the statutory guidelines and the reasonableness
test.” Ondrejack v. Ondrejack, 839 So. 2d 867, 871 (Fla. 4th DCA 2003).
Furthermore, “a trial court’s decisions about support must be supported
by competent substantial evidence and factual findings sufficient to enable
this court to determine how the trial court made the decisions it did.”
Lennon v. Lennon, 264 So. 3d 1084, 1085 (Fla. 2d DCA 2019). However,
“[w]hether a trial court’s mathematical computations are correct is a

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question of law which is reviewed de novo.” Kareff v. Kareff, 943 So. 2d
890, 892 (Fla. 4th DCA 2006).

   For purposes of adjusting an award of child support, a noncustodial
parent exercises a “substantial amount of time” when he or she exercises
time-sharing at least 20% of the overnights of the year. § 61.30(11)(b)8.,
Fla. Stat. (2019). “Where a child spends a substantial amount of time with
the noncustodial parent under a timesharing arrangement, a reduction in
that parent’s child support obligation is mandated.” Dillion v. Dep’t of
Revenue, Child Support Enf’t Program, 189 So. 3d 353, 354 (Fla. 4th DCA
2016); see also § 61.30(11)(b), Fla. Stat. (2019). This method of calculating
child support is referred to as the “gross-up method.” Rodriguez v. Medero,
17 So. 3d 867, 871 n.1 (Fla. 4th DCA 2009).

   Here, the trial court correctly calculated the child support amount to
be $750 per month before any consideration that the parties exercise a
substantial amount of time-sharing with the child. However, the trial
court failed to take the next step and apply the gross-up method.
See § 61.30(11)(b), Fla. Stat. (2019); Dillion, 189 So. 3d at 354. Based on
the time-sharing schedule, Father clearly spends more than 20% of
overnights in even-numbered years but less than 20% of overnights in
odd-numbered years. This requires a reduction in the child support owed
in even-numbered years.

   Based on the foregoing, we remand with instructions for the trial court
to recalculate the child support award and take into consideration the
substantial amount of time Father spends with the child in the
even-numbered years. Because the child support award will differ between
even and odd-numbered years, on remand, the trial court may order an
award that averages the two figures. See Lopez v. Lopez, 994 So. 2d 374,
375–76 (Fla. 3d DCA 2008) (holding that the trial court did not abuse its
discretion when it ordered an averaged amount of child support when the
father’s time-sharing with the children changed every year); see also
§ 61.30(11)(a)11., Fla. Stat. (2019) (providing that a court may make any
other adjustment to the total minimum child support “that is needed to
achieve an equitable result”).

   Affirmed in part and reversed and remanded in part.

LEVINE, C.J., and FORST, J., concur.

                            *          *       *

   Not final until disposition of timely filed motion for rehearing.


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