From catalog/rfc9110-http.abnf rule: If-Unmodified-Since

Definition

If-Unmodified-Since = HTTP-date

HTTP-date = IMF-fixdate / obs-date

obs-date = rfc850-date / asctime-date

rfc850-date = day-name-l "," SP date2 SP time-of-day SP GMT

day-name-l = %s"Monday" / %s"Tuesday" / %s"Wednesday" / %s"Thursday" / %s"Friday" / %s"Saturday" / %s"Sunday"

date2 = day "-" month "-" 2DIGIT

asctime-date = day-name SP date3 SP time-of-day SP year

date3 = month SP (2DIGIT / (SP DIGIT))

IMF-fixdate = day-name "," SP date1 SP time-of-day SP GMT

time-of-day = hour ":" minute ":" second

second = 2DIGIT

minute = 2DIGIT

hour = 2DIGIT

day-name = %s"Mon" / %s"Tue" / %s"Wed" / %s"Thu" / %s"Fri" / %s"Sat" / %s"Sun"

date1 = day SP month SP year

year = 4DIGIT

month = %s"Jan" / %s"Feb" / %s"Mar" / %s"Apr" / %s"May" / %s"Jun" / %s"Jul" / %s"Aug" / %s"Sep" / %s"Oct" / %s"Nov" / %s"Dec"

day = 2DIGIT

GMT = %s"GMT"

Info

Rulename
If-Unmodified-Since
Dependencies
GMT, SP, DIGIT, day, month, year, date1, day-name, hour, minute, second, time-of-day, IMF-fixdate, date3, asctime-date, date2, day-name-l, rfc850-date, obs-date, HTTP-date, If-Unmodified-Since
Used Builtins
DIGIT, SP

Alphabet

Translations

Railroad Diagram

If-Unmodified-Since HTTP-date

Swift Regular Expression

(Sun Ju[ln] |Thu Ju[ln] |Wed Ju[ln] |Tue Ju[ln] |(Sun F|Thu F|Wed F|Tue F)eb |(Sun M|Thu M|Wed M|Tue M)a[ry] |M(on Ju[ln] |on Feb |on Ma[ry] ))[ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|(Sun D|Thu D|Wed D|Tue D|Mon D)ec [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|((Sun N|Thu N|Wed N|Tue N)o|Mon No)v [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|(Sun Oc|Thu Oc|Wed Oc|Tue Oc|Mon Oc)t [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|Sa((t Ju[ln] |t Feb |t Ma[ry] )[ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|t Dec [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|t Nov [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|t Oct [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9])|(((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])([0-9] Ju[ln] |[0-9] Feb |[0-9] Ma[ry] )[0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |(Sund|Thursd|Wednesd|Tuesd|Mond)ay, [0-9][0-9](((-Ju[ln]|-Dec|-Feb|-Sep)-|-Ma[ry]-)[0-9]|-Nov-[0-9])[0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] Dec [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] Nov [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |(Sund|Thursd|Wednesd|Tuesd|Mond)ay, [0-9][0-9]-Oct-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] Oct [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |Sa(t, [0-9]([0-9] Ju[ln] |[0-9] Feb |[0-9] Ma[ry] )[0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |turday, [0-9][0-9](((-Ju[ln]|-Dec|-Feb|-Sep)-|-Ma[ry]-)[0-9]|-Nov-[0-9])[0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |t, [0-9][0-9] Dec [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |t, [0-9][0-9] Nov [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |turday, [0-9][0-9]-Oct-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |t, [0-9][0-9] Oct [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] ))GMT|((Sund|Thursd|Wednesd|Tuesd|Mond)ay, [0-9][0-9]-A|Saturday, [0-9][0-9]-A)ug-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|(((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] A|Sat, [0-9][0-9] A)ug [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|(Sun A|Thu A|Wed A|Tue A|Mon A|Sat A)ug [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|(((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] Se|Sat, [0-9][0-9] Se)p [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|((Sun S|Thu S|Wed S|Tue S)e|Mon Se|Sat Se)p [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|(Sun A|Thu A|Wed A|Tue A|Mon A|Sat A)pr [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|(((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] A|Sat, [0-9][0-9] A)pr [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|F(r((i Ju[ln] |i Feb |i Ma[ry] )[ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|i Dec [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|i Nov [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|i Oct [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9])|r(i, [0-9]([0-9] Ju[ln] |[0-9] Feb |[0-9] Ma[ry] )[0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |iday, [0-9][0-9](((-Ju[ln]|-Dec|-Feb|-Sep)-|-Ma[ry]-)[0-9]|-Nov-[0-9])[0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |i, [0-9][0-9] Dec [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |i, [0-9][0-9] Nov [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |iday, [0-9][0-9]-Oct-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |i, [0-9][0-9] Oct [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] )GMT|riday, [0-9][0-9]-Aug-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|ri, [0-9][0-9] Aug [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|ri Aug [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|ri, [0-9][0-9] Sep [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|ri Sep [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|ri Apr [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|ri, [0-9][0-9] Apr [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT)|(((Sund|Thursd|Wednesd|Tuesd|Mond)ay, [0-9][0-9]-A|Saturday, [0-9][0-9]-A)p|Friday, [0-9][0-9]-Ap)r-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|(((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] Ja|Sat, [0-9][0-9] Ja|Fri, [0-9][0-9] Ja)n [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|(Sun Ja|Thu Ja|Wed Ja|Tue Ja|Mon Ja|Sat Ja|Fri Ja)n [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|((Sund|Thursd|Wednesd|Tuesd|Mond)ay, [0-9][0-9]-Ja|Saturday, [0-9][0-9]-Ja|Friday, [0-9][0-9]-Ja)n-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT

POSIX Extended Regular Expression

(Sun Ju[ln] |Thu Ju[ln] |Wed Ju[ln] |Tue Ju[ln] |(Sun F|Thu F|Wed F|Tue F)eb |(Sun M|Thu M|Wed M|Tue M)a[ry] |M(on Ju[ln] |on Feb |on Ma[ry] ))[ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|(Sun D|Thu D|Wed D|Tue D|Mon D)ec [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|((Sun N|Thu N|Wed N|Tue N)o|Mon No)v [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|(Sun Oc|Thu Oc|Wed Oc|Tue Oc|Mon Oc)t [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|Sa((t Ju[ln] |t Feb |t Ma[ry] )[ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|t Dec [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|t Nov [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|t Oct [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9])|(((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])([0-9] Ju[ln] |[0-9] Feb |[0-9] Ma[ry] )[0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |(Sund|Thursd|Wednesd|Tuesd|Mond)ay, [0-9][0-9](((-Ju[ln]|-Dec|-Feb|-Sep)-|-Ma[ry]-)[0-9]|-Nov-[0-9])[0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] Dec [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] Nov [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |(Sund|Thursd|Wednesd|Tuesd|Mond)ay, [0-9][0-9]-Oct-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] Oct [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |Sa(t, [0-9]([0-9] Ju[ln] |[0-9] Feb |[0-9] Ma[ry] )[0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |turday, [0-9][0-9](((-Ju[ln]|-Dec|-Feb|-Sep)-|-Ma[ry]-)[0-9]|-Nov-[0-9])[0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |t, [0-9][0-9] Dec [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |t, [0-9][0-9] Nov [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |turday, [0-9][0-9]-Oct-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |t, [0-9][0-9] Oct [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] ))GMT|((Sund|Thursd|Wednesd|Tuesd|Mond)ay, [0-9][0-9]-A|Saturday, [0-9][0-9]-A)ug-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|(((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] A|Sat, [0-9][0-9] A)ug [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|(Sun A|Thu A|Wed A|Tue A|Mon A|Sat A)ug [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|(((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] Se|Sat, [0-9][0-9] Se)p [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|((Sun S|Thu S|Wed S|Tue S)e|Mon Se|Sat Se)p [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|(Sun A|Thu A|Wed A|Tue A|Mon A|Sat A)pr [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|(((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] A|Sat, [0-9][0-9] A)pr [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|F(r((i Ju[ln] |i Feb |i Ma[ry] )[ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|i Dec [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|i Nov [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|i Oct [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9])|r(i, [0-9]([0-9] Ju[ln] |[0-9] Feb |[0-9] Ma[ry] )[0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |iday, [0-9][0-9](((-Ju[ln]|-Dec|-Feb|-Sep)-|-Ma[ry]-)[0-9]|-Nov-[0-9])[0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |i, [0-9][0-9] Dec [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |i, [0-9][0-9] Nov [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |iday, [0-9][0-9]-Oct-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] |i, [0-9][0-9] Oct [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] )GMT|riday, [0-9][0-9]-Aug-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|ri, [0-9][0-9] Aug [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|ri Aug [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|ri, [0-9][0-9] Sep [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|ri Sep [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|ri Apr [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|ri, [0-9][0-9] Apr [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT)|(((Sund|Thursd|Wednesd|Tuesd|Mond)ay, [0-9][0-9]-A|Saturday, [0-9][0-9]-A)p|Friday, [0-9][0-9]-Ap)r-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|(((Sun, |Thu, |Wed, |Tue, )[0-9]|Mon, [0-9])[0-9] Ja|Sat, [0-9][0-9] Ja|Fri, [0-9][0-9] Ja)n [0-9][0-9][0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT|(Sun Ja|Thu Ja|Wed Ja|Tue Ja|Mon Ja|Sat Ja|Fri Ja)n [ 0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] [0-9][0-9][0-9][0-9]|((Sund|Thursd|Wednesd|Tuesd|Mond)ay, [0-9][0-9]-Ja|Saturday, [0-9][0-9]-Ja|Friday, [0-9][0-9]-Ja)n-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9] GMT