html forms and UTC time

rblampain · 08-17-2019, 06:40 AM

Is it possible to only have one of two HTML FORM options available in an HTML page according to UTC time (not visitor's local time)?

What I am trying to solve is that one of these two options should only be available to visitors on a particular day of the month in UTC time while the other option should be always available. This seems to be more a server-side issue but I can't figure how to start - css or Bash CGI or Javascript or whatever (I have not used PHP for more than ten years).

Alternatively, making the form available for a particular day of the month local (visitor's) time could be tested as a last resort.

Thank you for your help.

dugan · 08-17-2019, 09:35 AM

Have the server serve up a different form depending the date or time.

Also, keep in mind that "the visitor's local time" and "the server's UTC time" are the same time, just in different units. If you know one, you know the other.

michaelk · 08-17-2019, 11:09 AM

Displaying a form option based upon UTC should be fairly easy regardless of scripting language i.e PHP, bash or whatever. PHP has lots of ways to compare dates and a google search should find lots of information.

Server-side has no knowledge of a clients local time.

Code:

<form ...> 
...
<?php
#get date
#add special form option using checkbox as an example.
if ( $today=="some date" )
   print("<input type=checkbox name=\"special checkbox\" value=\"1\">");
?>
...
</form>

ondoho · 08-18-2019, 03:38 AM

Quote:

Originally Posted by dugan

Have the server serve up a different form depending the date or time.

"The server" being apache or nginx?
Can they be shoehorned to do that?

dugan · 08-18-2019, 05:18 PM

Quote:

Originally Posted by ondoho

"The server" being apache or nginx?

No, silly, the server being the BASH CGI that he mentioned.

scasey · 08-18-2019, 05:49 PM

Quote:

Originally Posted by rblampain

Is it possible to only have one of two HTML FORM options available in an HTML page according to UTC time (not visitor's local time)?

What I am trying to solve is that one of these two options should only be available to visitors on a particular day of the month in UTC time while the other option should be always available. This seems to be more a server-side issue but I can't figure how to start - css or Bash CGI or Javascript or whatever (I have not used PHP for more than ten years).

Alternatively, making the form available for a particular day of the month local (visitor's) time could be tested as a last resort.

Thank you for your help.

I would think that could be done with any server-side script. I'd try perl, but that's my go-to tool. michaelk's php example should work. Javascript could also work, I suppose. Wrap the once-a-month option in a div tag and only display that div on the appropriate day.