Text My Calendar

This Google Apps Script creates a simple SMS interface to Google Calendar.

Installation

Set up a Google Voice number and make sure it forwards texts to your email. This can be changed in your Google Voice settings under Voicemail & Text > Text Forwarding.
Create a Gmail filter to catch the Google Voice emails you receive when you text yourself. Label them with calendar.
Obtain a Twilio phone number and fill in the fields of twilio.gs with your Account SID, Auth Token, your Twilio phone number, and the phone number you'd like to receive notifications from. You can find the first two on your Twilio dashboard and the third on the Numbers tab.
Create a new project at http://script.google.com. Copy and paste the scripts into script files.
Set triggers (under Resources > Current project's triggers) to run main every minute. Note: the first time you do this, you will need to authorize the script to run.

Text your Google Voice number! If the first word of your text is not a keyword, Text My Calendar assumes that you are trying to add an event.

next: texts you the next appointment on your calendar.
five: texts you the five next appointments between now and the day after tomorrow.
tday: texts you the remaining appointments for today.
tomo: texts you all the appointments for tomorrow.

Text My Calendar uses Google Calendar's quick add to create an event. Text your calendar something like

Dinner with John tomorrow at 7 at Chez Panisse.