The Date Helper primarily creates select/option tags for different kinds of dates and date elements. All of the select-type methods share a number of common options that are as follows:

  • :prefix - overwrites the default prefix of "date" used for the select names. So specifying "birthday" would give birthday[month] instead of date[month] if passed to the select_month method.
  • :include_blank - set to true if it should be possible to set an empty date.
  • :discard_type - set to true if you want to discard the type part of the select name. If set to true, the select_month method would use simply "date" (which can be overwritten using :prefix) instead of "date[month]".
Methods
Constants
DEFAULT_PREFIX = "date" unless const_defined?("DEFAULT_PREFIX")
Public Instance methods
date_select(object, method, options = {})

Returns a set of select tags (one for year, month, and day) pre-selected for accessing a specified date-based attribute (identified by method) on an object assigned to the template (identified by object). It’s possible to tailor the selects through the options hash, which both accepts all the keys that each of the individual select builders does (like :use_month_numbers for select_month) and a range of discard options. The discard options are :discard_year, :discard_month and :discard_day. Set to true, they’ll drop the respective select. Discarding the month select will also automatically discard the day select. It’s also possible to explicitly set the order of the tags using the :order option with an array of symbols :year, :month and :day in the desired order. Symbols may be omitted and the respective select is not included.

NOTE: Discarded selects will default to 1. So if no month select is available, January will be assumed.

Examples:

  date_select("post", "written_on")
  date_select("post", "written_on", :start_year => 1995)
  date_select("post", "written_on", :start_year => 1995, :use_month_numbers => true,
                                    :discard_day => true, :include_blank => true)
  date_select("post", "written_on", :order => [:day, :month, :year])
  date_select("user", "birthday",   :order => [:month, :day])

The selects are prepared for multi-parameter assignment to an Active Record object.

    # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 70
70:       def date_select(object, method, options = {})
71:         InstanceTag.new(object, method, self).to_date_select_tag(options)
72:       end
datetime_select(object, method, options = {})

Returns a set of select tags (one for year, month, day, hour, and minute) pre-selected for accessing a specified datetime-based attribute (identified by method) on an object assigned to the template (identified by object). Examples:

  datetime_select("post", "written_on")
  datetime_select("post", "written_on", :start_year => 1995)

The selects are prepared for multi-parameter assignment to an Active Record object.

    # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 81
81:       def datetime_select(object, method, options = {})
82:         InstanceTag.new(object, method, self).to_datetime_select_tag(options)
83:       end
distance_of_time_in_words(from_time, to_time, include_seconds = false)
 Reports the approximate distance in time between to Time objects. For example, if the distance is 47 minutes, it'll return
 "about 1 hour". See the source for the complete wording list.

Set include_seconds to true if you want more detailed approximations if distance < 1 minute

    # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 19
19:       def distance_of_time_in_words(from_time, to_time, include_seconds = false)
20:         distance_in_minutes = ((to_time - from_time) / 60).round.abs
21:         distance_in_seconds = ((to_time - from_time)).round.abs
22: 
23:         case distance_in_minutes
24:           when 0..1
25:             return (distance_in_minutes==0) ? "less than a minute" : "1 minute" unless include_seconds
26:             case distance_in_seconds
27:               when 0..5   then "less than 5 seconds"
28:               when 6..10  then "less than 10 seconds"
29:               when 11..20 then "less than 20 seconds"
30:               when 21..40 then "half a minute"
31:               when 41..59 then "less than a minute"
32:               else             "1 minute"
33:             end
34:                                 
35:           when 2..45      then "#{distance_in_minutes} minutes"
36:           when 46..90     then "about 1 hour"
37:           when 90..1440   then "about #{(distance_in_minutes.to_f / 60.0).round} hours"
38:           when 1441..2880 then "1 day"
39:           else                 "#{(distance_in_minutes / 1440).round} days"
40:         end
41:       end
distance_of_time_in_words_to_now(from_time, include_seconds = false)

Alias for time_ago_in_words

select_date(date = Date.today, options = {})

Returns a set of html select-tags (one for year, month, and day) pre-selected with the date.

    # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 86
86:       def select_date(date = Date.today, options = {})
87:         select_year(date, options) + select_month(date, options) + select_day(date, options)
88:       end
select_datetime(datetime = Time.now, options = {})

Returns a set of html select-tags (one for year, month, day, hour, and minute) preselected the datetime.

    # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 91
91:       def select_datetime(datetime = Time.now, options = {})
92:         select_year(datetime, options) + select_month(datetime, options) + select_day(datetime, options) +
93:         select_hour(datetime, options) + select_minute(datetime, options)
94:       end
select_day(date, options = {})

Returns a select tag with options for each of the days 1 through 31 with the current day selected. The date can also be substituted for a hour number.

     # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 149
149:       def select_day(date, options = {})
150:         day_options = []
151: 
152:         1.upto(31) do |day|
153:           day_options << ((date && (date.kind_of?(Fixnum) ? date : date.day) == day) ?
154:             "<option value=\"#{day}\" selected=\"selected\">#{day}</option>\n" :
155:             "<option value=\"#{day}\">#{day}</option>\n"
156:           )
157:         end
158: 
159:         select_html("day", day_options, options[:prefix], options[:include_blank], options[:discard_type])
160:       end
select_hour(datetime, options = {})

Returns a select tag with options for each of the hours 0 through 23 with the current hour selected. The hour can also be substituted for a hour number.

     # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 134
134:       def select_hour(datetime, options = {})
135:         hour_options = []
136: 
137:         0.upto(23) do |hour|
138:           hour_options << ((datetime && (datetime.kind_of?(Fixnum) ? datetime : datetime.hour) == hour) ?
139:             "<option value=\"#{leading_zero_on_single_digits(hour)}\" selected=\"selected\">#{leading_zero_on_single_digits(hour)}</option>\n" :
140:             "<option value=\"#{leading_zero_on_single_digits(hour)}\">#{leading_zero_on_single_digits(hour)}</option>\n"
141:           )
142:         end
143: 
144:         select_html("hour", hour_options, options[:prefix], options[:include_blank], options[:discard_type])
145:       end
select_minute(datetime, options = {})

Returns a select tag with options for each of the minutes 0 through 59 with the current minute selected. Also can return a select tag with options by minute_step from 0 through 59 with the 00 minute selected The minute can also be substituted for a minute number.

     # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 119
119:       def select_minute(datetime, options = {})
120:         minute_options = []
121: 
122:         0.step(59, options[:minute_step] || 1) do |minute|
123:           minute_options << ((datetime && (datetime.kind_of?(Fixnum) ? datetime : datetime.min) == minute) ?
124:             "<option value=\"#{leading_zero_on_single_digits(minute)}\" selected=\"selected\">#{leading_zero_on_single_digits(minute)}</option>\n" :
125:             "<option value=\"#{leading_zero_on_single_digits(minute)}\">#{leading_zero_on_single_digits(minute)}</option>\n"
126:           )
127:         end
128: 
129:         select_html("minute", minute_options, options[:prefix], options[:include_blank], options[:discard_type])
130:       end
select_month(date, options = {})

Returns a select tag with options for each of the months January through December with the current month selected. The month names are presented as keys (what’s shown to the user) and the month numbers (1-12) are used as values (what’s submitted to the server). It’s also possible to use month numbers for the presentation instead of names — set the :use_month_numbers key in options to true for this to happen. If you want both numbers and names, set the :add_month_numbers key in options to true. Examples:

  select_month(Date.today)                             # Will use keys like "January", "March"
  select_month(Date.today, :use_month_numbers => true) # Will use keys like "1", "3"
  select_month(Date.today, :add_month_numbers => true) # Will use keys like "1 - January", "3 - March"
     # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 171
171:       def select_month(date, options = {})
172:         month_options = []
173: 
174:         1.upto(12) do |month_number|
175:           month_name = if options[:use_month_numbers]
176:             month_number
177:           elsif options[:add_month_numbers]
178:             month_number.to_s + " - " + Date::MONTHNAMES[month_number]
179:           else
180:             Date::MONTHNAMES[month_number]
181:           end
182: 
183:           month_options << ((date && (date.kind_of?(Fixnum) ? date : date.month) == month_number) ?
184:             %(<option value="#{month_number}" selected="selected">#{month_name}</option>\n) :
185:             %(<option value="#{month_number}">#{month_name}</option>\n)
186:           )
187:         end
188: 
189:         select_html("month", month_options, options[:prefix], options[:include_blank], options[:discard_type])
190:       end
select_second(datetime, options = {})

Returns a select tag with options for each of the seconds 0 through 59 with the current second selected. The second can also be substituted for a second number.

     # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 103
103:       def select_second(datetime, options = {})
104:         second_options = []
105: 
106:         0.upto(59) do |second|
107:           second_options << ((datetime && (datetime.kind_of?(Fixnum) ? datetime : datetime.sec) == second) ?
108:             "<option value=\"#{leading_zero_on_single_digits(second)}\" selected=\"selected\">#{leading_zero_on_single_digits(second)}</option>\n" :
109:             "<option value=\"#{leading_zero_on_single_digits(second)}\">#{leading_zero_on_single_digits(second)}</option>\n"
110:           )
111:         end
112: 
113:         select_html("second", second_options, options[:prefix], options[:include_blank], options[:discard_type])
114:       end
select_time(datetime = Time.now, options = {})

Returns a set of html select-tags (one for hour and minute)

    # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 97
97:       def select_time(datetime = Time.now, options = {})
98:         h = select_hour(datetime, options) + select_minute(datetime, options) + (options[:include_seconds] ? select_second(datetime, options) : '')
99:       end
select_year(date, options = {})

Returns a select tag with options for each of the five years on each side of the current, which is selected. The five year radius can be changed using the :start_year and :end_year keys in the options. The date can also be substituted for a year given as a number. Example:

  select_year(Date.today, :start_year => 1992, :end_year => 2007)
     # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 197
197:       def select_year(date, options = {})
198:         year_options = []
199:         y = date ? (date.kind_of?(Fixnum) ? (y = (date == 0) ? Date.today.year : date) : date.year) : Date.today.year
200:         default_start_year, default_end_year = y-5, y+5
201: 
202:         (options[:start_year] || default_start_year).upto(options[:end_year] || default_end_year) do |year|
203:           year_options << ((date && (date.kind_of?(Fixnum) ? date : date.year) == year) ?
204:             "<option value=\"#{year}\" selected=\"selected\">#{year}</option>\n" :
205:             "<option value=\"#{year}\">#{year}</option>\n"
206:           )
207:         end
208: 
209:         select_html("year", year_options, options[:prefix], options[:include_blank], options[:discard_type])
210:       end
time_ago_in_words(from_time, include_seconds = false)

Like distance_of_time_in_words, but where to_time is fixed to Time.now.

This method is also aliased as distance_of_time_in_words_to_now
    # File vendor/rails/actionpack/lib/action_view/helpers/date_helper.rb, line 44
44:       def time_ago_in_words(from_time, include_seconds = false)
45:         distance_of_time_in_words(from_time, Time.now, include_seconds)
46:       end