Convert string to datetime ruby on rails - ruby-on-rails

Question

I know this is basic but I've been struggling for a few hours now and I can't seem to apply one of the many ways there are to convert a string to datetime so I can save it in the database in this format 2018-03-16 00:12:17.555372. Thanks ahead
This is the string output in the console.
params[:event][:start_date]
"03/28/2018 1:46 AM"
[EDIT] Following some leads I've come up with smething really dirty maybe someone can help refactor I'm supressing AM or PM because I don't know how to parse that I know it's awfull any help is appreciated!
if !params[:event][:start_date].empty?
start_date = params[:event][:start_date]
start_date = start_date.gsub(/[AMP]/, '').squish
a = start_date.split('/')
tmp = a[0]
a[0] = a[1]
a[1] = tmp
a = a.split(',').join('/')
start_date = Time.parse(a)
end
if !params[:event][:end_date].empty?
end_date = params[:event][:end_date]
end_date = end_date.gsub(/[AMP]/, '').squish
a = end_date.split('/')
tmp = a[0]
a[0] = a[1]
a[1] = tmp
a = a.split(',').join('/')
end_date = Time.parse(a)
end

Answer 1

You can use DateTime to parse the date from a specific format.
if the format you are looking to parse is "03/28/2018 1:46 AM" then you can do this.
date = DateTime.strptime('03/28/2018 1:46 AM', '%m/%d/%Y %I:%M %p')
# date to ISO 8601
puts date.to_time
# output: 2018-03-28 07:16:00 +0530
puts date.strftime("%m/%d/%Y")
# output: 03/28/2018
Date formats:
Date (Year, Month, Day):
%Y - Year with century (can be negative, 4 digits at least)
-0001, 0000, 1995, 2009, 14292, etc.
%m - Month of the year, zero-padded (01..12)
%_m blank-padded ( 1..12)
%-m no-padded (1..12)
%d - Day of the month, zero-padded (01..31)
%-d no-padded (1..31)
Time (Hour, Minute, Second, Subsecond):
%H - Hour of the day, 24-hour clock, zero-padded (00..23)
%k - Hour of the day, 24-hour clock, blank-padded ( 0..23)
%I - Hour of the day, 12-hour clock, zero-padded (01..12)
%l - Hour of the day, 12-hour clock, blank-padded ( 1..12)
%P - Meridian indicator, lowercase (``am'' or ``pm'')
%p - Meridian indicator, uppercase (``AM'' or ``PM'')
%M - Minute of the hour (00..59)
You can refer to all formats here.

Answer 2

You can parse it like so in ruby:
Parses the given representation of date and time, and creates a DateTime object. This method does not function as a validator.
DateTime.parse('2001-02-03T04:05:06+07:00')
#=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.parse('20010203T040506+0700')
#=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.parse('3rd Feb 2001 04:05:06 PM')
#=> #<DateTime: 2001-02-03T16:05:06+00:00 ...>
Not entirely sure if the string you supplied can be parsed, here is the link to the ruby docs on datetimes Docs