try
set oldDelims to AppleScript's text item delimiters -- save their current state
set AppleScript's text item delimiters to {":"} -- declare new delimiters

display dialog "What would you like to be reminded about?" default answer ""
set reminder_input to text returned of result --get input

set reminder_items to every text item of reminder_input --parse input

if the number of items in reminder_items is greater than 1 then --check if input contains a :
set reminder_name to text item 2 of reminder_items --use text after : as reminder subject
set reminder_time to (current date) + (text item 1 of reminder_items) * hours --use text before : as due date in hours
else
set reminder_name to text item 1 of reminder_items --if there is no :, use all input as subject
set reminder_time to (current date) + 2 * hours -- default reminder is in 2 hours --default to due date of 2 hours
end if

--if the button returned of the result is "OK" then
tell application "Reminders"
-- set reminder_name to (text returned of result)
set reminder_id to make new reminder with properties {remind me date:reminder_time, name:reminder_name} --create reminder
end tell
set AppleScript's text item delimiters to oldDelims -- restore delimiters
--end if
on error
set AppleScript's text item delimiters to oldDelims -- restore delimiters
display dialog "Something went wrong. Check your syntax!" --throw an error if something goes wrong
end try