Do you understand this code?

renderCards.js

loadItems(day) {
    setTimeout(() => {
      for (let i = -15; i < 85; i++) {
        const time = day.timestamp + i * 24 * 60 * 60 * 1000;
        const strTime = this.timeToString(time);
        // console.log('time', time);
        // console.log('day', day);
        // console.log('strTime', strTime);
        if (!this.state.items[strTime]) {
          this.state.items[strTime] = [];
          const numItems = Math.floor(Math.random() * 5);
          for (let j = 0; j < numItems; j++) {
            // console.log(dummy.data[j]);
            this.state.items[strTime].push({
              name: `Item for${strTime}`,
              day,
              dummy: dummy.data[j],
              height: Math.max(50, Math.floor(Math.random() * 150))
            });
          }
        }
      }
      //arr of obj of displayed
      console.log('.', this.state.items);
      const newItems = {};
      Object.keys(this.state.items).forEach(key => { newItems[key] = this.state.items[key]; });
      this.setState({
        items: newItems
      });
    }, 1000);
    console.log(`Load Items for ${day.year}-${day.month}`);
  }