diff --git a/main.c b/main.c
index 1af55d8..274f1e9 100644
--- a/main.c
+++ b/main.c
@@ -175,67 +175,74 @@ void switch_activity(activity *activities, U32 *current_activity, activity_type
     }
 }
 
+struct tm *today()
+{
+    U64 secs = now();
+    struct tm *t = localtime((time_t *)(&secs));
+    t->tm_hour = 0;
+    t->tm_min  = 0;
+    t->tm_sec  = 0;
+    return t;
+}
+
+U64 start_of_day_seconds(struct tm *t)
+{
+    // NOTE: Technically, this can fail only if the year is >2038 on 32-bit
+    //       platforms as size_t--a 32-bit--value would overflow. ON 64-bit,
+    //       this is a non-issue.
+    time_t ts = mktime(t);
+    return ts;
+}
+
+char *get_dir()
+{
+    local_persist char buffer[128];
+    snprintf(buffer, sizeof(buffer), "%s/.timetracker", get_home_dir());
+    return buffer;
+}
+
+char *get_date_str(struct tm *t)
+{
+    local_persist char buffer[16];
+    strftime(buffer, sizeof(buffer), "%Y_%m_%d", t);
+    return buffer;
+}
+
+char *get_file(char *dir, struct tm *t)
+{
+    local_persist char buffer[256];
+    snprintf(buffer, sizeof(buffer), "%s/%s", dir, get_date_str(t));
+    return buffer;
+}
+
 int main(int argc, char *argv[])
 {
-    activity activities[100];
+    activity activities[256]; // TODO: This should be a dynamic array.
     memset(activities, 0, sizeof(activities));
     U32 current_activity = 0;
 
     Activity_Stat activities_stats[activity_type_COUNT];
     memset(activities_stats, 0, sizeof(activities_stats));
 
-    U64 secs = now();
-    struct tm *t = localtime((time_t *)(&secs));
-    t->tm_hour = 0;
-    t->tm_min  = 0;
-    t->tm_sec  = 0;
+    struct tm *t = today();
+    U64 ts = start_of_day_seconds(t);
 
-    time_t ts = mktime(t);
-    if(ts == (time_t)-1) {
-        fprintf(stderr, "mktime failed.\n");
+    char *dir_path = get_dir();
+    char *file_path = get_file(dir_path, t);
+
+    if(!is_directory(dir_path)) {
+        mkdir(dir_path, 0700); // WARNING: Might fail, what then?
+    }
+
+    FILE *f;
+    f = fopen(file_path, "r+");
+    if(!f) {
+        fprintf(stderr, "fopen(%s) failed: %s\n", file_path, strerror(errno));
         return 1;
     }
 
-    // TODO: Clean up.
-    // TODO: Clean up.
-    // TODO: Clean up.
-
-    // Check if 2025-02-10 available
-    // build array
-    // then, save the file periodically (every ~5 seconds)
-    // TODO: Make global constant or in config file
-    char date_buffer[16];
-    char dir_buffer[128];
-    char file_buffer[256];
-
-    strftime(date_buffer, sizeof(date_buffer), "%Y_%m_%d", t);
-    snprintf(dir_buffer, sizeof(dir_buffer), "%s/.timetracker",
-             get_home_dir());
-    snprintf(file_buffer, sizeof(file_buffer), "%s/%s", dir_buffer,
-             date_buffer);
-
-    if(!is_directory(dir_buffer)) {
-        mkdir(dir_buffer, 0700); // WARNING: Might fail, what then?
-    }
-
-    // TODO: Fix error handling.
-    // WARNING: Not bullet proof, yet.
-    FILE *f;
-    if(path_exists(file_buffer)) {
-        f = fopen(file_buffer, "r");
-        if(!f) {
-            fprintf(stderr, "fopen(%s) failed: %s\n", file_buffer,
-                    strerror(errno));
-            return 1;
-        }
-    } else {
-        f = fopen(file_buffer, "w+");
-    }
-
     char line[4096];
-    if(file_size(f) < 1) {
-        printf("EMPTY\n");
-    } else {
+    if(file_size(f) > 0) {
         while(fgets(line, sizeof line, f)) {
             size_t n = strcspn(line, "\r\n");
             line[n] = '\0';
@@ -281,7 +288,7 @@ int main(int argc, char *argv[])
 
     U64 last_save = 0;
 
-    U64 lower_bound_s = (U64)ts;
+    U64 lower_bound_s = ts;
     U64 upper_bound_s = lower_bound_s + 86400;
     // U64 upper_bound_s = lower_bound_s + 3600;
 
@@ -318,34 +325,21 @@ int main(int argc, char *argv[])
     while(!WindowShouldClose()) {
         U64 now_s = now();
 
-        // NOTE: WARNING: TODO: Temporary solution; to be cleaned up.
         if(now_s >= upper_bound_s) {
-            U64 secs = now();
+            t = today();
+            ts = start_of_day_seconds(t);
 
-            t = localtime((time_t *)(&secs));
-            t->tm_hour = 0;
-            t->tm_min  = 0;
-            t->tm_sec  = 0;
-
-            time_t ts = mktime(t);
-            if(ts == (time_t)-1) {
-                fprintf(stderr, "mktime failed.\n");
-                return 1;
-            }
-
-            lower_bound_s = (U64)ts;
+            lower_bound_s = ts;
             upper_bound_s = lower_bound_s + 86400;
 
             fclose(f);
 
-            strftime(date_buffer, sizeof(date_buffer), "%Y_%m_%d", t);
-            snprintf(file_buffer, sizeof(file_buffer), "%s/%s", dir_buffer,
-                     date_buffer);
+            file_path = get_file(dir_path, t);
 
-            f = fopen(file_buffer, "w+");
+            f = fopen(file_path, "r");
             if(!f) {
-                fprintf(stderr, "Failed to create file: %s\n", file_buffer);
-                return 1;
+                fprintf(stderr, "Failed to create file: %s\n", file_path);
+                return 1; // TODO: REMOVE.
             }
 
             activity_type type = activities[current_activity].type;
@@ -384,41 +378,23 @@ int main(int argc, char *argv[])
             DrawRectangle(0, 0, window_w, 40, GRAY);
 
             for(U32 i = 0; i <= current_activity; i++) {
-                F32 start_x =
-                    floor((F32)(activities[i].began - lower_bound_s) /
-                        (F32)(upper_bound_s - lower_bound_s) * (F32)window_w);
-                F32 end_x =
-                    floor(((F32)(activities[i].ended - lower_bound_s) /
-                        (F32)(upper_bound_s - lower_bound_s)) * window_w);
-                DrawRectangle(start_x, 0, end_x - start_x, 40,
-                              activities[i].color);
+                F32 start_x = floor((F32)(activities[i].began - lower_bound_s) / (F32)(upper_bound_s - lower_bound_s) * (F32)window_w);
+                F32 end_x = floor(((F32)(activities[i].ended - lower_bound_s) / (F32)(upper_bound_s - lower_bound_s)) * window_w);
+                DrawRectangle(start_x, 0, end_x - start_x, 40, activities[i].color);
             }
 
-            // TODO: CLEAN UP.
-            F32 width =
-                (window_w-padding_x*(float)(activity_type_COUNT+1)) /
-                    (float)activity_type_COUNT;
+            F32 width = (window_w-padding_x*(float)(activity_type_COUNT+1)) / (float)activity_type_COUNT;
 
             for(U32 i = 0; i <= current_activity; i++) {
-                activities_stats[activities[i].type].total_seconds +=
-                    activities[i].ended - activities[i].began;
+                activities_stats[activities[i].type].total_seconds += activities[i].ended - activities[i].began;
             }
 
             for(U32 i = 0; i < activity_type_COUNT; i ++) {
                 Hours time = break_time(activities_stats[i].total_seconds);
-                snprintf(activities_stats[i].seconds_str,
-                         sizeof(activities_stats[i].seconds_str),
-                         "%02llu:%02llu:%02llu",
-                         time.hours, time.minutes, time.seconds);
-                
-                Rectangle rect =
-                    { (padding_x*(i+1))+(width*i), 60, width, (window_h-70) };
-                if(activity_button(rect,
-                    activity_type_string_representation[i],
-                    activities_stats[i].seconds_str, font_size,
-                    (activities[current_activity].type == i ? WHITE : BLACK),
-                    activity_type_color_representation[i]))
-                {
+                snprintf(activities_stats[i].seconds_str, sizeof(activities_stats[i].seconds_str), "%02llu:%02llu:%02llu", time.hours, time.minutes, time.seconds);
+
+                Rectangle rect = { (padding_x*(i+1))+(width*i), 60, width, (window_h-70) };
+                if(activity_button(rect, activity_type_string_representation[i], activities_stats[i].seconds_str, font_size, (activities[current_activity].type == i ? WHITE : BLACK), activity_type_color_representation[i])) {
                     if(activities[current_activity].type != i) {
                         switch_activity(activities, &current_activity, i, now_s);
                     }
@@ -428,9 +404,7 @@ int main(int argc, char *argv[])
 
                 char index_buf[8];
                 snprintf(index_buf, sizeof(index_buf), "%d", i + 1);
-                DrawTextEx(state.font, index_buf,
-                           (Vector2){ rect.x + 10.0f, rect.y + 10.0f },
-                           font_size - 5.0f, 2, BLACK);
+                DrawTextEx(state.font, index_buf, (Vector2){ rect.x + 10.0f, rect.y + 10.0f }, font_size - 5.0f, 2, BLACK);
             }
         EndDrawing();
 
@@ -439,29 +413,24 @@ int main(int argc, char *argv[])
             activities_stats[activities[i].type].total_seconds = 0;
         }
 
-        // WARNING: This is error prone.
         // Save the state every 5 seconds.
         if((now_s - last_save) >= 5) {
-            f = freopen(file_buffer, "w", f); // WARNING: TODO: Might fail.
+            f = freopen(file_path, "w+", f); // NOTE: We want to clear file contents before the next write.
+            if(f) {
+                char write_buffer[128];
+                for(U32 i = 0; i <= current_activity; i++) {
+                    snprintf(write_buffer, sizeof(write_buffer), "%s %llu %llu\n", activity_type_string_representation[activities[i].type], activities[i].began, activities[i].ended);
 
-            char write_buffer[128];
-            for(U32 i = 0; i <= current_activity; i++) {
-                snprintf(write_buffer, sizeof(write_buffer),
-                    "%s %llu %llu\n",
-                    activity_type_string_representation[activities[i].type],
-                    activities[i].began,
-                    activities[i].ended);
-
-                size_t write_buffer_len = strlen(write_buffer);
-                if(fwrite(write_buffer, 1, write_buffer_len, f) !=
-                    write_buffer_len)
-                {
-                    perror("fwrite");
+                    size_t write_buffer_len = strlen(write_buffer);
+                    if(fwrite(write_buffer, 1, write_buffer_len, f) != write_buffer_len) {
+                        // NOTE: We do not care, probably for now, that it might have failed to write some data.
+                        //       The program will either overwrite everything again or the next launch will ignore the corrupted line.
+                    }
                 }
-            }
 
-            if(fflush(f) != 0)
-                perror("fflush");
+                if(fflush(f) != 0)
+                    perror("fflush");
+            }
 
             last_save = now_s;
         }