Refactor, update UI, and add notes

lib/date.ts

@@ -0,0 +1,80 @@
+const months = [
+    'January',
+    'February',
+    'March',
+    'April',
+    'May',
+    'June',
+    'July',
+    'August',
+    'September',
+    'October',
+    'November',
+    'December'
+];
+
+const ordSfx = ['','st','nd','rd','th'];
+
+function toHumanReadableDate(date: Date | string, disable?: {year?: boolean, month?: boolean, day?: boolean}) {
+    const oDate = (typeof date === 'string')? new Date(date): date;
+
+    const year = oDate.getFullYear();
+    const month = months[oDate.getMonth()];
+    const day = oDate.getDate();
+    
+    let sfx;
+    if (day >= 1 && day <= 3)
+        sfx = ordSfx[day];
+    else
+        sfx = ordSfx[4];
+    
+    let out = !disable?.day ? `${day}${sfx}` : '';
+    out = !disable?.month ? `${out} ${month}` : out;
+    out = !disable?.year ? `${out} ${year}` : out;
+
+    return out;
+}
+
+function toRelativeDate(date: Date | string): string { 
+    const oDate = (typeof date === 'string')? new Date(date): date;
+
+    const now = new Date();
+    const diff = now.getTime() - oDate.getTime();
+
+    let tdiff = Math.floor(diff/1000);
+    
+    if (tdiff < 0) {
+        return toHumanReadableDate(oDate);
+    }
+
+    if (tdiff < 60) {
+        return `${tdiff} seconds ago`;
+    }
+    
+    tdiff = Math.floor(tdiff/60);
+    if (tdiff < 60) {
+        return `${tdiff} minute${tdiff === 1? '' : 's'} ago`;
+    }
+
+    tdiff = Math.floor(tdiff/60);
+    if (tdiff < 24) {
+        return `${tdiff} hour${tdiff === 1? '' : 's'} ago`;
+    }
+    if (tdiff < 48) {
+        return `Yesterday`;
+    }
+
+    if (oDate.getFullYear() != now.getFullYear())
+        return toHumanReadableDate(oDate);
+    return toHumanReadableDate(oDate, {year: true});
+}
+
+function isValid(date: any) {
+    return (new Date(date)).toString() === 'Invalid Date';
+}
+const DateTool = {
+    toRelativeDate, 
+    isValid
+};;
+
+export default DateTool;