1 files changed, 146 insertions, 0 deletions
diff --git a/std/datetime/mod.ts b/std/datetime/mod.ts
new file mode 100644
index 000000000..efa6e09fe
--- /dev/null
+++ b/std/datetime/mod.ts
@@ -0,0 +1,146 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import { pad } from "../strings/pad.ts";
+
+export type DateFormat = "mm-dd-yyyy" | "dd-mm-yyyy" | "yyyy-mm-dd";
+
+/**
+ * Parse date from string using format string
+ * @param dateStr Date string
+ * @param format Format string
+ * @return Parsed date
+ */
+export function parseDate(dateStr: string, format: DateFormat): Date {
+  let m, d, y: string;
+  let datePattern: RegExp;
+
+  switch (format) {
+    case "mm-dd-yyyy":
+      datePattern = /^(\d{2})-(\d{2})-(\d{4})$/;
+      [, m, d, y] = datePattern.exec(dateStr)!;
+      break;
+    case "dd-mm-yyyy":
+      datePattern = /^(\d{2})-(\d{2})-(\d{4})$/;
+      [, d, m, y] = datePattern.exec(dateStr)!;
+      break;
+    case "yyyy-mm-dd":
+      datePattern = /^(\d{4})-(\d{2})-(\d{2})$/;
+      [, y, m, d] = datePattern.exec(dateStr)!;
+      break;
+    default:
+      throw new Error("Invalid date format!");
+  }
+
+  return new Date(Number(y), Number(m) - 1, Number(d));
+}
+
+export type DateTimeFormat =
+  | "mm-dd-yyyy hh:mm"
+  | "dd-mm-yyyy hh:mm"
+  | "yyyy-mm-dd hh:mm"
+  | "hh:mm mm-dd-yyyy"
+  | "hh:mm dd-mm-yyyy"
+  | "hh:mm yyyy-mm-dd";
+
+/**
+ * Parse date & time from string using format string
+ * @param dateStr Date & time string
+ * @param format Format string
+ * @return Parsed date
+ */
+export function parseDateTime(
+  datetimeStr: string,
+  format: DateTimeFormat
+): Date {
+  let m, d, y, ho, mi: string;
+  let datePattern: RegExp;
+
+  switch (format) {
+    case "mm-dd-yyyy hh:mm":
+      datePattern = /^(\d{2})-(\d{2})-(\d{4}) (\d{2}):(\d{2})$/;
+      [, m, d, y, ho, mi] = datePattern.exec(datetimeStr)!;
+      break;
+    case "dd-mm-yyyy hh:mm":
+      datePattern = /^(\d{2})-(\d{2})-(\d{4}) (\d{2}):(\d{2})$/;
+      [, d, m, y, ho, mi] = datePattern.exec(datetimeStr)!;
+      break;
+    case "yyyy-mm-dd hh:mm":
+      datePattern = /^(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2})$/;
+      [, y, m, d, ho, mi] = datePattern.exec(datetimeStr)!;
+      break;
+    case "hh:mm mm-dd-yyyy":
+      datePattern = /^(\d{2}):(\d{2}) (\d{2})-(\d{2})-(\d{4})$/;
+      [, ho, mi, m, d, y] = datePattern.exec(datetimeStr)!;
+      break;
+    case "hh:mm dd-mm-yyyy":
+      datePattern = /^(\d{2}):(\d{2}) (\d{2})-(\d{2})-(\d{4})$/;
+      [, ho, mi, d, m, y] = datePattern.exec(datetimeStr)!;
+      break;
+    case "hh:mm yyyy-mm-dd":
+      datePattern = /^(\d{2}):(\d{2}) (\d{4})-(\d{2})-(\d{2})$/;
+      [, ho, mi, y, m, d] = datePattern.exec(datetimeStr)!;
+      break;
+    default:
+      throw new Error("Invalid datetime format!");
+  }
+
+  return new Date(Number(y), Number(m) - 1, Number(d), Number(ho), Number(mi));
+}
+
+/**
+ * Get number of the day in the year
+ * @return Number of the day in year
+ */
+export function dayOfYear(date: Date): number {
+  const dayMs = 1000 * 60 * 60 * 24;
+  const yearStart = new Date(date.getFullYear(), 0, 0);
+  const diff =
+    date.getTime() -
+    yearStart.getTime() +
+    (yearStart.getTimezoneOffset() - date.getTimezoneOffset()) * 60 * 1000;
+  return Math.floor(diff / dayMs);
+}
+
+/**
+ * Get number of current day in year
+ * @return Number of current day in year
+ */
+export function currentDayOfYear(): number {
+  return dayOfYear(new Date());
+}
+
+/**
+ * Parse a date to return a IMF formated string date
+ * RFC: https://tools.ietf.org/html/rfc7231#section-7.1.1.1
+ * IMF is the time format to use when generating times in HTTP
+ * headers. The time being formatted must be in UTC for Format to
+ * generate the correct format.
+ * @param date Date to parse
+ * @return IMF date formated string
+ */
+export function toIMF(date: Date): string {
+  function dtPad(v: string, lPad = 2): string {
+    return pad(v, lPad, { char: "0" });
+  }
+  const d = dtPad(date.getUTCDate().toString());
+  const h = dtPad(date.getUTCHours().toString());
+  const min = dtPad(date.getUTCMinutes().toString());
+  const s = dtPad(date.getUTCSeconds().toString());
+  const y = date.getUTCFullYear();
+  const days = ["Sun", "Mon", "Tue", "Wed", "Thus", "Fri", "Sat"];
+  const months = [
+    "Jan",
+    "Feb",
+    "Mar",
+    "May",
+    "Jun",
+    "Jul",
+    "Aug",
+    "Sep",
+    "Oct",
+    "Nov",
+    "Dec"
+  ];
+  return `${days[date.getUTCDay()]}, ${d} ${
+    months[date.getUTCMonth()]
+  } ${y} ${h}:${min}:${s} GMT`;
+}