// extensions. Equals max lang (3) + script (4) + max reg (3) + 2 dashes.
	maxCoreSize = 12

	// max99thPercentileSize is a somewhat arbitrary buffer size that presumably
	// is large enough to hold at least 99% of the BCP 47 tags.
	max99thPercentileSize = 32

	// maxSimpleUExtensionSize is the maximum size of a -u extension with one
	// key-type pair. Equals len("-u-") + key (2) + dash + max value (8).
	maxSimpleUExtensionSize = 14

	{95, "ENOTSUP", "operation not supported"},
	{96, "EPFNOSUPPORT", "protocol family not supported"},
	{97, "EAFNOSUPPORT", "address family not supported by protocol"},
	{98, "EADDRINUSE", "address already in use"},
	{99, "EADDRNOTAVAIL", "cannot assign requested address"},
	{100, "ENETDOWN", "network is down"},
	{101, "ENETUNREACH", "network is unreachable"},
	{102, "ENETRESET", "network dropped connection on reset"},

	{95, "ENOTSUP", "operation not supported"},
	{96, "EPFNOSUPPORT", "protocol family not supported"},
	{97, "EAFNOSUPPORT", "address family not supported by protocol"},
	{98, "EADDRINUSE", "address already in use"},
	{99, "EADDRNOTAVAIL", "cannot assign requested address"},
	{100, "ENETDOWN", "network is down"},
	{101, "ENETUNREACH", "network is unreachable"},
	{102, "ENETRESET", "network dropped connection on reset"},

	{95, "ENOTSUP", "operation not supported"},
	{96, "EPFNOSUPPORT", "protocol family not supported"},
	{97, "EAFNOSUPPORT", "address family not supported by protocol"},
	{98, "EADDRINUSE", "address already in use"},
	{99, "EADDRNOTAVAIL", "cannot assign requested address"},
	{100, "ENETDOWN", "network is down"},
	{101, "ENETUNREACH", "network is unreachable"},
	{102, "ENETRESET", "network dropped connection on reset"},

	//
	// (b) gives us periodicity if the watch breaks due to unexpected
	// conditions, (a) ensures that on timeout the watcher is as close to
	// now as possible - this covers 99% of cases.

	if !c.wasBookmarkAfterRvReceived() {
		return time.Time{}, true // schedule immediately
	}

	heartbeatTime := now.Add(bookmarkFrequency)
	if c.deadline.IsZero() {

	{94, "ECHRNG", "channel number out of range"},
	{95, "EL2NSYNC", "level 2 not synchronized"},
	{96, "EL3HLT", "level 3 halted"},
	{97, "EL3RST", "level 3 reset"},
	{98, "ELNRNG", "link number out of range"},
	{99, "EUNATCH", "protocol driver not attached"},
	{100, "ENOCSI", "no CSI structure available"},
	{101, "EL2HLT", "level 2 halted"},
	{102, "EBADE", "invalid exchange"},
	{103, "EBADR", "invalid request descriptor"},

	{95, "ENOTSUP", "operation not supported"},
	{96, "EPFNOSUPPORT", "protocol family not supported"},
	{97, "EAFNOSUPPORT", "address family not supported by protocol"},
	{98, "EADDRINUSE", "address already in use"},
	{99, "EADDRNOTAVAIL", "cannot assign requested address"},
	{100, "ENETDOWN", "network is down"},
	{101, "ENETUNREACH", "network is unreachable"},
	{102, "ENETRESET", "network dropped connection on reset"},

	{95, "ENOTSUP", "operation not supported"},
	{96, "EPFNOSUPPORT", "protocol family not supported"},
	{97, "EAFNOSUPPORT", "address family not supported by protocol"},
	{98, "EADDRINUSE", "address already in use"},
	{99, "EADDRNOTAVAIL", "cannot assign requested address"},
	{100, "ENETDOWN", "network is down"},
	{101, "ENETUNREACH", "network is unreachable"},
	{102, "ENETRESET", "network dropped connection on reset"},

	{95, "ENOTSUP", "operation not supported"},
	{96, "EPFNOSUPPORT", "protocol family not supported"},
	{97, "EAFNOSUPPORT", "address family not supported by protocol"},
	{98, "EADDRINUSE", "address already in use"},
	{99, "EADDRNOTAVAIL", "cannot assign requested address"},
	{100, "ENETDOWN", "network is down"},
	{101, "ENETUNREACH", "network is unreachable"},
	{102, "ENETRESET", "network dropped connection on reset"},

            year = matcher.group(1).toInt()
          }
        }

        pos = dateCharacterOffset(s, end + 1, limit, false)
      }

      // Convert two-digit years into four-digit years. 99 becomes 1999, 15 becomes 2015.
      if (year in 70..99) year += 1900
      if (year in 0..69) year += 2000

      // If any partial is omitted or out of range, return -1. The date is impossible. Note that leap