Alfred Hart made the case for an approximate two hour time limit to plays in the early modern period, a view that is still prevalent, and which has implications for understanding of how much of Shakespeare's plays would have been performed versus how much would have been cut, and why he (or his contemporaries) would have written plays so much longer than 2400-3000 lines if they knew they would be severely cut for performance. Theatrical performance was, however, more flexible than common wisdom suggests, and likely could have accommodated full performances of even a long play (159).
Hart and Erne argue for strict two hour running times based on the average length of plays by playwrights other than Jonson or Shakespeare, but fail to account for playgoing as a theatrical event that included more entertainment than the play proper. Such a theatrical event could have lasted almost four hours; such conditions may have favored a longer play (159 - 160).
cf. Klein, David. "Time Alloted for an Elizabethan Performance." Shakespeare Quarterly 18 (1967): 434-438.
Hart estimates that the speaking time for verse is about 20 lines per minute, which is what the American Shakespeare Center regularly achieves in performance, and when experimenting with early modern pronunciation has achieved slightly higher rates of delivery, so Hart's estimation should be regarded as "about right." (160 - 161; quoted text on 160).
Before the mid-1590s, London companies performed after evening prayer, which typically ran from about 2 PM to about 3:30 PM. Stage performances began "towards fower a clock" (Chambers, Elizabethan Stage, 4:316), and would regularly be in progress at 6:00, which we know because the great earthquake of 1580 struck at about 6 PM and interrupted performance at both the Theatre and the Curtain. Plays in winter "routinely continued past dark," even at outdoor, public theatres (161).
Performances could have lasted as late as 8 PM, as evidenced by an assembly of insubordinate apprentices on 11 June 1592 at "abowt viij of the clock" (Chambers, Elizabethan Stage, 4:310) (162).
After the mid-1590s, plays would begin around 2 PM, but would similarly last about four hours. Thomas Platter, a Swiss visitor to London in 1599, attests to this (see Chambers 2:364). Other sources indicate that audiences sometimes began to gather at about 1 PM (162 - 163).
It is plausible that pre-show entertainments might have begun at about 2 PM, but the play proper might not have commenced until about 3 PM, which would account for the line in Robert Dawes' contract with the owners of the Hope that he be ready to begin the play at 3 PM (164 - 165).
A January 1619 petition to the city government of London, signed by "ministers and citizens of the Blackfriars precinct," complains that coaches fill the streets "from one or twoe of the clock till sixe att night" (165).
Shakespeare makes a reference to the passage of time in The Tempest. Early in the play, Prospero notes that the time is "
John Rowe reports a 1653 production of Mucedorus by a semi-professional group that lasted about three hours, despite the relative brevity of the extant play text (174).
Elizabethans did not measure time as precisely as we tend to in the modern era. Personal time pieces were rare, as were minute hands, and most people would have measured time by the hourly-ringing of church bells. two-bells could have rung in either an hour and two minutes or two hours and 58 minutes (175).
Thirteen plays from the early modern period are identified as taking two hours to perform. The shortest of these is The Hog Hath Lost His Pearl, which has 1951 lines. The longest is The Alchemist, which at 3066 lines just barely edges out Romeo and Juliet, the second longest at 2989 (175).
The majority of the incidental entertainments offered during theatrical events are likely to have been instrumental music pieces, but juggling, tumbling, sword dancing, singing, clowning, and contests of wit may have also been common (176).
Historical sources agree on the play beginning at the third sounding of a trumpet, and the first being used to indicate that the playhouse was open, but the timing of the third sounding was imprecise. The start time of the play would be partially determined by the length of pre-show entertainments (177).
Acting companies varied the time they spent on such [incidental] entertainment in inverse proportion to the time they devoted to the plays, a practice that explains much conflicting evidence (181).
Given the approximately four hours available for a theatrical event, a play that long would, by Hart's calculus, need to be about 3900 lines long, and none of Shakespeare's, and only a few of Jonson's, ar that long (181 - 182).
The theatrical event of early modern London comprised of about four hours time, and generally more than the play itself. In the case of shorter plays, such as Merry Devil, it may therefore be possible that the play was printed more or less as performed, and perhaps that the play was not performed alone. One act plays are commonly, in modern times, presented in groups, and it is not inconceivable that early modern Londoners might have enjoyed the same thing. In any case, Merry Devil is a short play, far shorter than the time that would have been alloted to its performance, especially given its popularity.
Hirrel, Michael J. "Duration of Performances and Lengths of Plays: How Shall We Beguile the Lazy Time?" Shakespeare Quarterly. Vol 61. No 2. Summer 2010. p 159 - 182. Print.