This structure can be used to hold the test data.
Make an array of Test structures.

struct Test {
	char date1[16];
	char date2[16];
	int expected_days;
};

                              expected
    known input data           output
--------------------------  ------------
 date-1        date-2       days between
------------  ------------  ------------
"11-05-2024", "11-06-2024", 1,
"11-05-2024", "11-30-2024", 25,
"11-05-2024", "12-01-2024", 26,
"11-05-2024", "01-01-2025", 57,
"01-01-2024", "11-05-2024", 309,
"11-05-2024", "11-05-2025", 365,
"01-01-2024", "01-01-2025", 366,
"01-01-2000", "11-05-2024", 9075,
"03-08-3637", "04-22-7058", 1249539,
"11-17-0485", "03-24-6240", 2101732,
"02-11-0389", "10-19-7886", 2738473,
"01-20-2096", "04-17-8851", 2467300,
"05-04-0675", "08-03-9144", 3093330,
"09-13-3121", "03-01-6747", 1324173,
"09-19-0039", "07-12-8226", 2990171,
"12-24-7810", "01-02-8373", 205276,
"10-14-1889", "11-18-3900", 734537,
"02-20-2131", "07-04-2146", 5613,
"10-05-2455", "06-04-9577", 2601134,
"05-12-4939", "04-30-7471", 924782,
"02-14-0772", "09-10-2349", 576196,
"06-13-2930", "04-21-6076", 1149001,
"01-10-3892", "08-08-7582", 1347955,
"05-04-9682", "11-21-9696", 5315,
"05-22-3507", "04-11-4385", 320643,
"09-25-4559", "03-01-7964", 1243443,
"09-18-0414", "03-15-5201", 1748229,
"09-15-2737", "03-23-6388", 1333325,
"03-06-7090", "02-23-9685", 947794,
"05-04-3544", "01-02-9928", 2331585,
"01-20-0782", "12-02-4448", 1339296,
"12-11-6101", "06-16-7980", 686113,
"06-18-0866", "01-03-0898", 11522,
"01-16-4458", "05-04-6191", 633073,
"08-29-0887", "12-24-3363", 904457,
"01-17-1368", "06-14-3183", 663063,
"12-18-0116", "01-22-4503", 1601988,
"02-15-1458", "11-18-8616", 2614682,
"11-15-3926", "03-03-5007", 394570,
"08-09-0675", "07-11-9179", 3105993,
"12-03-3794", "03-10-3821", 9593,
"11-27-5787", "04-05-6172", 140383,
"07-05-7437", "12-22-7797", 131658,
"02-07-1018", "10-14-6883", 2142397,
"05-03-3324", "11-19-6857", 1290602,
"12-09-2069", "06-22-5186", 1138290,
"06-20-2377", "03-19-7094", 1722746,
"08-02-7082", "06-28-7727", 235546,
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