diff --git a/28.5.2_zeitadd.c b/28.5.2_zeitadd.c
new file mode 100644
index 0000000..042085a
--- /dev/null
+++ b/28.5.2_zeitadd.c
@@ -0,0 +1,35 @@
+#include <stdio.h>
+struct zeit {
+    int tag;
+    int std;
+    int min;
+    int sek;
+};
+unsigned long zeit_in_sek(struct zeit z) {
+    return z.tag * 86400 + z.std * 3600 + z.min * 60 + z.sek;
+}
+struct zeit sek_in_zeit(unsigned long sek) {
+    struct zeit z;
+    z.tag = sek / 86400;
+    sek %= 86400;
+    z.std = sek / 3600;
+    sek %= 3600;
+    z.min = sek / 60;
+    z.sek = sek % 60;
+    return z;
+}
+int main() {
+    struct zeit z1, z2, summe;
+    unsigned long s1, s2, sgesamt;
+    printf("Gib 1. Zeit ein (tt.hh.mm.ss): ");
+    scanf("%d.%d.%d.%d", &z1.tag, &z1.std, &z1.min, &z1.sek);
+    printf("Gib 2. Zeit ein (tt.hh.mm.ss): ");
+    scanf("%d.%d.%d.%d", &z2.tag, &z2.std, &z2.min, &z2.sek);
+    s1 = zeit_in_sek(z1);
+    s2 = zeit_in_sek(z2);
+    sgesamt = s1 + s2;
+    summe = sek_in_zeit(sgesamt);
+    printf("= %d Tage, %d:%d:%d; %lu Gesamtsekunden\n",
+           summe.tag, summe.std, summe.min, summe.sek, sgesamt);
+    return 0;
+}
\ No newline at end of file
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