An appropriate time series model for predicting passenger data of Djalaluddin Gorontalo Airport, the interval between 2003 - 2017 with the multiplicative of Holt’s-Winters’ exponential smoothing as
Y
^
t
+
p
=
(
L
t
+
p
T
t
)
S
t
−
12
+
p
, where for time t, the original exponential smoothing data,
L
t
=
0.2
Y
t
S
t
−
12
+
0.8
(
L
t
−
1
+
T
t
−
1
)
, smoothing trend patterns Tt
= 0.2(Lt
− L
t−1) + 0.8T
t−1 and smoothing seasonal patterns,
S
t
=
0.2
Y
t
L
t
+
0.8
S
t
−
12
, so the smoothing parameter used are α = β = γ = 0.2. After several treatments, the mean square deviation (MSD) is 3287241 for arrival passenger data and MSD is 2490279 for passenger departure data with a seasonal length of 12 by do not event-based. The next, the MSD is 1334585 for arrival passenger data and MSD is 1433867 for passenger departure data with a seasonal length of 12 by Eid al-Fitr event-based, the MSD is 1259600 for arrival passenger data and MSD is 1252548 for passenger departure data with a seasonal length of 12 by Eid al-Adha event-based.