Locking cells in Google Sheets at a specific time - google-apps-script

Question

I want to code my Google Sheets cells in a way that certain cells automatically lock at a specific time every day. I should be able to edit it, but not my collaborators.
How do I pull this off?
In the sample sheet (link here), you will see certain dates (15/7/2015-17/7/2015). I want to code it so that each date (eg A1:B6) is locked daily, 10 pm.

Answer 1

As #NightShadeQueen suggested a combination of Time-driven triggers and the protect()-method of the Class Range can be used.
Open the script editor in the sheet (Tools > Script editor...)
Create code that locks the ranges, might look something like this:
You'll have to modify the code if your sheet doesn't look like the Sample sheet. Especially the lockRanges()-function, which defines which ranges should be protected. Currently, it starts with cell A1, and steps down 7 rows at a time until the end of the sheet is reached.
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheetByName('Sheet1'); //INSERT SHEET NAME HERE
function lockRanges() {
//First cell to lock
var row = 1;
var col = 1;
// Get last row with data in sheet
var lastRow = sheet.getLastRow();
//Loop until last row in sheet is passed
while(row <= lastRow){
//Lock current cell
lockRange(row, col);
// Go to row 7 steps down from current (the next date)
row = row + 7;
}
}
function lockRange(row, col){
var range = sheet.getRange(row, col);
// Create protection object. Set description, anything you like.
var protection = range.protect().setDescription('Protected, row ' + row);
// Ensure the current user is an editor before removing others. Otherwise, if the user's edit
// permission comes from a group, the script will throw an exception upon removing the group.
var me = Session.getEffectiveUser();
protection.addEditor(me);
protection.removeEditors(protection.getEditors());
if (protection.canDomainEdit()) {
protection.setDomainEdit(false);
}
}
Add the Time-driven trigger
Still in the Script editor; go to Resources > Current project's triggers.
Create a new trigger
Choose Run = lockRanges
Choose Events = Time-driven, Day timer, 10pm to 11pm (or whenever you want)
NOTE: The time may be slightly randomized (read more)
That's it, now the ranges will be protected at the time you chose. As with ranges you protect manually, they show up in Data > Protected sheets and ranges.
Something unclear? Ask away!