/*
* Abbreviated version of the yacc grammar used by at(1).
*/

%token <charval> DOTTEDDATE
%token <charval> HYPHENDATE
%token <charval> HOURMIN
%token <charval> INT1DIGIT
%token <charval> INT2DIGIT
%token <charval> INT4DIGIT
%token <charval> INT5_8DIGIT
%token <charval> INT
%token NOW
%token AM PM
%token NOON MIDNIGHT TEATIME
%token SUN MON TUE WED THU FRI SAT
%token TODAY TOMORROW
%token NEXT
%token MINUTE HOUR DAY WEEK MONTH YEAR
%token JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
%token UTC

%type <charval> concatenated_date
%type <charval> hr24clock_hr_min
%type <charval> int1_2digit
%type <charval> int2_or_4digit
%type <charval> integer
%type <intval> inc_dec_period
%type <intval> inc_dec_number
%type <intval> day_of_week

%start timespec
%%
timespec : spec_base
| spec_base inc_or_dec
;

spec_base : date
| time
| time date
| NOW
;

time : time_base
| time_base timezone_name
;

time_base : hr24clock_hr_min
| time_hour am_pm
| time_hour_min
| time_hour_min am_pm
| NOON
| MIDNIGHT
| TEATIME
;

hr24clock_hr_min: INT4DIGIT
;

time_hour : int1_2digit
;

time_hour_min : HOURMIN
;

am_pm : AM
| PM
;

timezone_name : UTC
;

date : month_name day_number
| month_name day_number year_number
| month_name day_number ',' year_number
| day_of_week
| TODAY
| TOMORROW
| HYPHENDATE
| DOTTEDDATE
| day_number month_name
| day_number month_name year_number
| month_number '/' day_number '/' year_number
| concatenated_date
| NEXT inc_dec_period
| NEXT day_of_week
;

concatenated_date: INT5_8DIGIT
;

month_name : JAN | FEB | MAR | APR | MAY | JUN
| JUL | AUG | SEP | OCT | NOV | DEC
;

month_number : int1_2digit
;

day_number : int1_2digit
;

year_number : int2_or_4digit
;

day_of_week : SUN | MON | TUE | WED | THU | FRI | SAT
;

inc_or_dec : increment | decrement
;

increment : '+' inc_dec_number inc_dec_period
;

decrement : '-' inc_dec_number inc_dec_period
;

inc_dec_number : integer
;

inc_dec_period : MINUTE | HOUR | DAY | WEEK | MONTH | YEAR
;

int1_2digit : INT1DIGIT | INT2DIGIT
;

int2_or_4digit : INT2DIGIT | INT4DIGIT
;

integer : INT | INT1DIGIT | INT2DIGIT | INT4DIGIT | INT5_8DIGIT
;

%%